Answer:
1. The balanced equation is 2KCIO3 → 2KCI + 3O2. According to the law of conservation of mass, the mass of the reactants must equal the mass of the products. Therefore, the mass of oxygen produced is:
Mass of oxygen = Mass of KCIO3 - Mass of KCI
Mass of oxygen = 500 g - 303 g
Mass of oxygen = 197 g
Therefore, 197 g of O2 are produced.
2. The balanced equation is N2 + 3H2 → 2NH3. We need to find out how much H2 is needed to react with 100 g of N2 to produce 121 g of NH3. First, we need to calculate the number of moles of N2 and NH3:
Moles of N2 = Mass of N2 / Molar mass of N2
Moles of N2 = 100 g / 28 g/mol
Moles of N2 = 3.57 mol
Moles of NH3 = Mass of NH3 / Molar mass of NH3
Moles of NH3 = 121 g / 17 g/mol
Moles of NH3 = 7.12 mol
According to the balanced equation, 1 mole of N2 reacts with 3 moles of H2 to produce 2 moles of NH3. Therefore, the number of moles of H2 needed is:
Moles of H2 = Moles of N2 x (3/1)
Moles of H2 = 3.57 mol x 3
Moles of H2 = 10.71 mol
Finally, we can calculate the mass of H2 needed:
Mass of H2 = Moles of H2 x Molar mass of H2
Mass of H2 = 10.71 mol x 2 g/mol
Mass of H2 = 21.42 g
Therefore, 21.42 g of H2 are needed.
3. The balanced equation is 4Fe + 3O2 → 2Fe2O3. We need to find out how much oxygen is needed to react with 350 g of Fe to produce 500 g of Fe2O3. First, we need to calculate the number of moles of Fe and Fe2O3:
Moles of Fe = Mass of Fe / Molar mass of Fe
Moles of Fe = 350 g / 55.85 g/mol
Moles of Fe = 6.26 mol
Moles of Fe2O3 = Mass of Fe2O3 / Molar mass of Fe2O3
Moles of Fe2O3 = 500 g / 159.69 g/mol
Moles of Fe2O3 = 3.13 mol
According to the balanced equation, 4 moles of Fe react with 3 moles of O2 to produce 2 moles of Fe2O3. Therefore, the number of moles of O2 needed is:
Moles of O2 = Moles of Fe x (3/4)
Moles of O2 = 6.26 mol x (3/4)
Moles of O2 = 4.69 mol
Finally, we can calculate the mass of O2 needed:
Mass of O2 = Moles of O2 x Molar mass of O2
Mass of O2 = 4.69 mol x 32 g/mol
Mass of O2 = 150.08 g
Therefore, 150.08 g of O2 are needed.
4. The balanced equation is CH2 + 2O2 → CO2 + 2H2O. We know that 16 g of CH2 reacts with 64 g of O2 to produce 44 g of CO2. We need to find out how much water is produced. First, we need to calculate the number of moles of CH2 and CO2:
Moles of CH2 = Mass of CH2 / Molar mass of CH2
Moles of CH2 = 16 g / 14 g/mol
Moles of CH2 = 1.14 mol
Moles of CO2 = Mass of CO2 / Molar mass of CO2
Moles of CO2 = 44 g / 44 g/mol
Moles of CO2 = 1 mol
According to the balanced equation, 1 mole of CH2 reacts with 2 moles of O2 to produce 2 moles of H2O. Therefore, the number of moles of H2O produced is:
Moles of H2O = Moles of CH2 x (2/1)
Moles of H2O = 1.14 mol x 2
Moles of H2O = 2.28 mol
Finally, we can calculate the mass of H2O produced:
Mass of H2O = Moles of H2O x Molar mass of H2O
Mass of H2O = 2.28 mol x 18 g/mol
Mass of H2O = 41.04 g
Therefore, 41.04 g of H2O are produced.
5. The balanced equation is CaCO3 → CaO + CO2. We need to find out how much CO2 is produced from the decomposition of 200 g of CaCO3 if 112 g of CaO are produced. First, we need to calculate the number of moles of CaCO3 and CaO:
Moles of CaCO3 = Mass of CaCO3 / Molar mass of CaCO3
Moles of CaCO3 = 200 g / 100.09 g/mol
Moles of CaCO3 = 1.999 mol
Moles of CaO = Mass of CaO / Molar mass of CaO
Moles of CaO = 112 g / 56.08 g/mol
Moles of CaO = 1.999 mol
According to the balanced equation, 1 mole of CaCO3 produces 1 mole of CaO and 1 mole of CO2. Therefore, the number of moles of CO2 produced is:
Moles of CO2 = Moles of CaCO3 x (1/1)
Moles of CO2 = 1.999 mol
Finally, we can calculate the mass of CO2 produced:
Mass of CO2 = Moles of CO2 x Molar mass of CO2
Mass of CO2 = 1.999 mol x 44 g/mol
Mass of CO2 = 87.96 g
Therefore, 87.96 g of CO2 are produced.
What is the percent of Ca in
Ca(C2H3O2)2?
(Ca = 40.08 g/mol, C = 12.01 g/mol,
H= 1.01 g/mol, O = 16.00 g/mol)
[?] % Ca
Answer:
25.3%
Explanation:
Since
Ca has just 1 mole
Ca ×1 = 40.08
C has 4 moles
C×4 = 48.04
H has 6 moles
H×6 = 6.06
O has 4 moles
O×4 = 64
64+6.06+48.04+40.08=158 (approx.)
40.08÷158 ×100% = 25.3%
uestion 8 Calculate the percentage by mass of hydrogen in PtCl2(NH3)2 A. 1.558 B. 1.008 c.0.672 D. 0.034 E.2.016
The percentage by mass of hydrogen can be calculated from the problem as 2.016
How do you calculate the mass percent of an atom in a compound?To calculate the mass percent of an atom in a compound, you first need to determine the molar mass of the compound and the molar mass of the atom of interest.
Determine the molar mass of the compound by adding up the atomic masses of all the atoms in the compound.
Determine the number of moles of the atom of interest in one mole of the compound. This is done by dividing the atomic mass of the atom by the molar mass of the compound.
We know that the relative molecular mas of the compound is; 300 g/mol
Then;
Percent by mass of hydrogen is; 6/300 * 100/1
= 2.016%
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What is the IUPAC-name for this thing?
The IUPAC name for the compound given in the question is 2,3-dibromo-5-methylheptane
How do i determine the IUPAC name for the compound?The IUPAC name for compound can be obtained by using the following steps:
Locate the longest continuous carbon chain. In this case it is carbon 7. Hence, the parent name is heptaneIdentify the substituent groups attached. In this case the substituent groups attached are: Br and CH₃ Give the substituents the best possible low count. In this case, there are two Br groups located at carbon 2 and 3 while the CH₃ is located at carbon 5Combine the above to obtain the IUPAC name for the compound.Thus, the IUPAC name for the compound is: 2,3-dibromo-5-methylheptane
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How many molecules of HCI are in 4.91 L of HCI acid at 25°C if the density equals 1.096 g/ml
To determine the number of HCl molecules in 4.91 L of HCl acid at 25°C, we can use the following steps:
Calculate the mass of the HCl acid in 4.91 L using its density.Convert the mass of HCl acid to the number of moles using its molar mass.Use Avogadro's number to convert the number of moles of HCl to the number of HCl molecules.Calculate the mass of the HCl acid in 4.91 L using its density:[tex]\qquad\sf {Density = \dfrac{mass}{volume}}[/tex]
[tex]\qquad\sf{mass = density \times volume}[/tex]
[tex]\qquad\sf{mass = 1.096 \: g/mL \times 4.91\: L = 5.38\: kg}[/tex]
Convert the mass of HCl acid to the number of moles using its molar mass. The molar mass of HCl is 36.46 g/mol.
[tex]\sf{moles = \dfrac{mass}{ molar\: mass} = \dfrac{5.38\: kg}{36.46\: g/mol} = 147.6\: mol}[/tex]
Use Avogadro's number to convert the number of moles of HCl to the number of HCl molecules. Avogadro's number is [tex]6.02 \times 10^23[/tex] molecules/mol.
[tex]\sf number\: of\: HCl\: molecules = moles \times Avogadro's\: number[/tex]
[tex]\begin{aligned}\sf number\: of\: HCl\: molecules& =\sf 147.6 \: mol \times 6.02 \times 10^23\: molecules/mol \\& =\sf 8.88 \times 10^25\: molecules\end{aligned}[/tex]
Therefore, there are [tex]8.88 \times 10^25[/tex] HCl molecules in 4.91 L of HCl acid at 25°C, assuming the density of the acid is 1.096 g/mL.
[tex]\rule{200pt}{5pt}[/tex]
Write a balanced chemical equation for the reaction between aqueous hydrogen ion, H+, and aqueous hydroxide ion, OH+
H+ (aq) + OH- (aq) → H2O (l)
Effect of Solvent:
Record the results.
H2O =
alcohol =
glycerin =
In which liquid is the salt most soluble?
Using the concept of `'Like dissolves like," explain why you got the results you did.
Explain how the choice of solvent affects the dissolving process.
Effect of Pulverizing:
Record of dissolving times.
crystal =
pulverized =
Why are the dissolving rates different?
Effect of Temperature:
Record of dissolving times.
cold =
hot
Using the concepts of kinetic energy, describe why you found the results you did.
Effect of Stirring:
Record the times necessary to dissolve each sample.
Record of dissolving time.
stirred =
unstirred =
Perform the experiment again using hot tap water this time. Are there any differences in the results between the cold water experiment and the hot water experiment? Explain.
Conclusions:
Review the four factors of dissolving you have just investigated. Given the correct solvent for a solute, what could you do to hasten the solution process?
1.
2.
3.
To hasten the solution process, we can choose the correct solvent for the solute, pulverize the solute to increase its surface area, increase the temperature of the solvent.
Effect of Solvent:
H2O = most soluble
alcohol = least soluble
glycerin = intermediate solubility
The salt is most soluble in water because salt is an ionic compound and water is a polar solvent. "Like dissolves like" means that substances with similar polarity and intermolecular forces tend to dissolve each other. Water is a polar solvent, meaning it has a partial positive charge on one end and a partial negative charge on the other, while salt is an ionic compound made up of positively and negatively charged ions. The partial charges on the water molecule can interact with the ions of salt, causing the salt to dissolve.
The choice of solvent affects the dissolving process because it determines the ability of the solvent to interact with the solute. Solvents that are similar in polarity and intermolecular forces to the solute tend to dissolve the solute more easily.
Effect of Pulverizing:
crystal = longest dissolving time
pulverized = shortest dissolving time
The dissolving rates are different because pulverizing the salt increases its surface area, exposing more salt to the solvent and allowing for a greater opportunity for the solute-solvent interactions to occur.
Effect of Temperature:
cold = longest dissolving time
hot = shortest dissolving time
Increasing the temperature of the solvent increases the kinetic energy of the solvent molecules, which leads to more frequent and energetic collisions with the solute particles, resulting in faster dissolving rates.
Effect of Stirring:
stirred = shorter dissolving time
unstirred = longer dissolving time
Stirring increases the rate of the dissolving process by helping to disperse the solute particles evenly throughout the solvent, increasing the surface area of the solute that is in contact with the solvent, and promoting the mixing of the solute and solvent.
Conclusions:
To hasten the solution process, we can choose the correct solvent for the solute, pulverize the solute to increase its surface area, increase the temperature of the solvent, and stir the solution to disperse the solute particles evenly throughout the solvent.
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Problem 1. What masses of 15% and 20% solutions are needed to prepare 200 g of 17% solution?
Problem 2. What masses of 18% and 5% solutions are needed to prepare 300 g of 7% solution?
Problem 3. 200 g of 15% and 350 g of 20% solutions were mixed. Calculate mass percentage of final solution.
Problem 4. 300 g of 15% solution and 35 g of solute were mixed. Calculate mass percentage of final solution.
Problem 5. 400 g of 25% solution and 150 g of water were mixed. Calculate mass percentage of final solution.
For each problem:
Masses of solution needed are 80 g and 120 g respectively.Masses of solution needed are 120 g and 180 g respectively.Mass percentage of final solution is 22.7%.Mass percentage of final solution is 23.9%Mass percentage of final solution is 18.2%.How to calculate mass and mass percentage?Problem 1:
Let x be the mass of the 15% solution needed and y be the mass of the 20% solution needed.
We have two equations:
x + y = 200 (total mass of the solution)
0.15x + 0.20y = 0.17(200) (total amount of solute in the solution)
Solving these equations:
x = 80 g (mass of 15% solution needed)
y = 120 g (mass of 20% solution needed)
Therefore, 80 g of 15% solution and 120 g of 20% solution need to be mixed to prepare 200 g of 17% solution.
Problem 2:
Let x be the mass of the 18% solution needed and y be the mass of the 5% solution needed.
We have two equations:
x + y = 300 (total mass of the solution)
0.18x + 0.05y = 0.07(300) (total amount of solute in the solution)
Solving these equations:
x = 120 g (mass of 18% solution needed)
y = 180 g (mass of 5% solution needed)
Therefore, 120 g of 18% solution and 180 g of 5% solution need to be mixed to prepare 300 g of 7% solution.
Problem 3:
Let x be the mass of the final solution.
The total amount of solute in the final solution is:
0.15(200 g) + 0.20(350 g) = 55 g + 70 g = 125 g
The total mass of the final solution is:
200 g + 350 g = 550 g
Therefore, the mass percentage of the final solution is:
(125 g / 550 g) x 100% = 22.7%
Problem 4:
Let x be the mass of the final solution.
The total amount of solute in the final solution is:
0.15(300 g) + 35 g = 80 g
The total mass of the final solution is:
300 g + 35 g = 335 g
Therefore, the mass percentage of the final solution is:
(80 g / 335 g) x 100% = 23.9%
Problem 5:
Let x be the mass of the final solution.
The total amount of solute in the final solution is:
0.25(400 g) = 100 g
The total mass of the final solution is:
400 g + 150 g = 550 g
Therefore, the mass percentage of the final solution is:
(100 g / 550 g) x 100% = 18.2%
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What is the total number of moles of reactants and products in the
chemical reaction listed below:
2 H₂S +30₂2 H₂O + 2 SO₂
The total number of moles of reactants and products in the chemical reaction given is 9 moles
How do i determine the total number of moles?The total number of mole of reactants and products in the chemical reaction can be obtained as follow:
2H₂S + 3O₂ -> 2H₂O + 2SO₂
The following were obtained from the above equation:
Mole of H₂S = 2 molesMole of O₂ = 3 molesMole of H₂O = 2 molesMole of SO₂ = 2 molesMole of reactants = Mole of (H₂S + O₂) = 2 + 3 = 5 molesMole of products = Mole of (H₂O + SO₂) = 2 + 2 = 4 molesTotal number of moles =?Total number of mole = Mole of reactants + mole of products
Total number of mole = 5 mole + 4 moles
Total number of mole = 9 moles
Thus, we can say that the total number of mole is 9 moles
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Based on your knowledge of Earth History, what event in geologic history do you think is recorded in the Allamuchy Pond sediments? Explain using evidence from the image. ( Use a CER format )
Based on the image given, scientists identified each type of pollen to study what types of plants were living in the area at different times in the past.
Why are the Allamuchy Pond sediments important?Pond sediment can preserve valuable historical data. Layers of sedimentary information can be used to provide a chronology of the history of a pond site. Allamuchy Pond sediments have been studied for their paleoclimate and paleoenvironmental information. Allamuchy Pond sediments have been dated to the Pleistocene epoch, which lasted from about 2.6 million to 11,700 years ago. The Pleistocene was characterized by repeated cycles of glaciation and deglaciation, and it is possible that the sediments in Allamuchy Pond contain evidence of these cycles, such as glacial deposits or variations in sediment composition related to changes in climate. Additionally, the sediments may contain information about changes in local vegetation, water levels, or other environmental factors that occurred during the Pleistocene.
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Alexander, who weighs 180 lb , decides to climb Mt. Krumpett, which is 5620 m
high. For his food supply, he decides to take nutrition bars. The label on the bars states that each 100-g bar contains 10 g of fat, 40 g of protein, and 50 g of carbohydrates. One gram of fat contains 9 Calories, whereas each gram of protein and carbohydrates contains 4 Calories.
To determine how much food to bring, Alexander will need to take into account the energy required to climb the mountain. Gravitational potential energy is the energy stored in an object that is raised to a height. The gravitational potential energy is related to an object's mass m, the height h to which it is raised, and the acceleration due to gravity, g. The relationship is given by E=m⋅g⋅h
The value of g near Earth's surface is 9.81m/s2.
Alexander wants to know exactly how many bars to pack in his backpack for the journey. To provide a margin of safety, he assumes that he will need as much energy for the return trip as for the uphill climb. How many bars should Alexander pack?
Answer: Brainlest Please!
Explanation:
To determine how many bars Alexander should pack, we first need to calculate the energy required for the uphill climb and the return trip. We can use the formula for gravitational potential energy to calculate this:
Energy required = m * g * h
where m is the mass of Alexander and his backpack, g is the acceleration due to gravity, and h is the height of the mountain.
First, we need to convert Alexander's weight from pounds to kilograms:
180 lb * (1 kg / 2.205 lb) = 81.65 kg
Assuming Alexander's backpack weighs 10 kg, his total mass is:
m = 81.65 kg + 10 kg = 91.65 kg
Next, we need to convert the height of the mountain from meters to joules:
5620 m * 91.65 kg * 9.81 m/s^2 = 5,029,669 J
Since Alexander assumes he will need as much energy for the return trip, the total energy required is:
2 * 5,029,669 J = 10,059,338 J
Now, we can calculate the number of bars required to provide this amount of energy.
Each bar weighs 100 g, and contains 10 g of fat, 40 g of protein, and 50 g of carbohydrates.
First, we need to calculate the total energy per bar:
10 g of fat * 9 Cal/g + 40 g of protein * 4 Cal/g + 50 g of carbohydrates * 4 Cal/g = 410 Cal
Next, we can calculate the number of bars required:
10,059,338 J * (1 Cal / 4.184 J) * (1 bar / 410 Cal) = 605 bars
Therefore, Alexander should pack approximately 605 nutrition bars for his trip up and down Mt. Krumpett.
. Using appropriate illustrations, explain how structural factors affect the reaction outcome in
conjugate addition reactions.
Nucleophilic addition that targets the C=C double bond's electrophilic carbon is known as conjugate addition in,-unsaturated systems.
What kind of response is that?Changes in temperature, gas production, precipitant formation, and color are common components of chemical reactions. Cooking, digesting, and combustion are a few straightforward examples of common reactions.
What exactly is a chemical reaction?When atoms' chemical bonds are established or ruptured, chemical processes take place. The materials that initiate a chemical change are known as reactants, while the materials created as a result of the reaction as known as products.
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The mass of a hydrate is 12.75g. The hydrate is heated and the resulting mass of the
anhydrate is 9.87g. Calculate the experimental percentage of water by mass.
The experimental percentage of water by mass, given that the hydrate is heated and it produces 9.87 g of anhydrous, is 22.6%
How do i determine the experimental percentage of water?First, we shall determine the mass of the water in the hydrate. Details below:
Mass of hydrate = 12.75 gMass of anhydrous = 9.87 gMass of water = ?Mass of water = Mass of hydrate - Mass of anhydrous
Mass of water = 12.75 - 9.87
Mass of water = 2.88
Finally, we shall determine the experimental percentage of water by mass. Details below:
Mass of water = 2.88Mass of hydrate = 12.75 gExperimental percentage of water =?Experimental percentage of water = (mass of of water / mass of hydrate) × 100
Experimental percentage of water = (2.88 / 12.75) × 100
Experimental percentage of water = 22.6%
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Part 1: How many oxygen atoms are in one mole of the formula Al2(CO3)3?
Part 2: How many moles of carbon are in 3.5 moles of calcium carbonate?
There are therefore a total of 14 atoms: 2 Al, 3 C, & 9 O. In other words, 3.5 moles of calcium carbonate will contain 3.5 moles if carbon because each mole of calcium carbonate has one mole of carbon.
How is carbon in CaCO3 calculated?Hence, 40.078 divided by 100.086 everything multiplied by 100% represents the mass percentage for calcium in calcium carbonate. This yields a value of almost 40%. Carbon's mass percentage is calculated by taking 12.011 and dividing it by 100.086, then multiplying that result by 100% to get a number of roughly 12 percent.
How many oxygen atoms make up Al2O3?The subscripts (2 and 3) in this formula indicate how so many atoms will make up one unit of the molecule. There are two aluminium atoms and three oxygen atoms, respectively, denoted by the numbers 2 and 3.
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What's the difference between magnesium and Aluminum?
Answer:
The key difference between aluminum and magnesium is that the aluminum is a corrosion resistant metal whereas magnesium is not. Magnesium and aluminum are two chemical elements that we can categorize as metals in the periodic table. Both are naturally occurring metals in different mineral forms.
Explanation:
Which of these is not a sign of a chemical reaction?
1. The material dissolves
2. Heat is released
3. A gas is given off
A chemical reaction is known by;
2. Heat is released
3. A gas is given off
How do you know a chemical reaction?A change in color may indicate that a chemical reaction has occurred. For example, when iron is exposed to air and moisture, it rusts and turns from silver to reddish-brown.
If a gas is produced during a reaction, it can indicate that a chemical reaction has occurred. For example, when baking soda is mixed with vinegar, carbon dioxide gas is produced, which causes bubbles to form.
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A bottle of nail polish remover containing ethyl acetate was spilled in an unventilated room measuring 9.00 m × 6.00 m × 3.00 m. After some time had passed, it was determined that 8.701 g of ethyl acetate had evaporated. Calculate the concentration of ethyl acetate in milligrams per cubic meter.
Answer:
53.69 mg/m³
Explanation:
To calculate the concentration of ethyl acetate in milligrams per cubic meter, we need to know the total volume of the room and the amount of ethyl acetate that evaporated in grams.
The total volume of the room is:
V = l x w x h
V = 9.00 m x 6.00 m x 3.00 m
V = 162.00 cubic meters
To convert the amount of ethyl acetate evaporated from grams to milligrams, we multiply by 1000:
amount of ethyl acetate = 8.701 g = 8,701 mg
Now we can calculate the concentration of ethyl acetate in milligrams per cubic meter:
concentration = amount of ethyl acetate / volume of room
concentration = 8,701 mg / 162.00 cubic meters
concentration = 53.69 mg/m³
Therefore, the concentration of ethyl acetate in the unventilated room is 53.69 mg/m³.
Which of the following are the products and reactants of a chemical reaction most likely to have in common?
1. Atoms
2. Molecules
3. Chemical properties
Answer:
1. Atoms
Explanation:
The products and reactants of a chemical reaction are usually related in terms of their atoms and molecules. During a chemical reaction, atoms are rearranged to form new molecules, and these new molecules are the products of the reaction. However, the atoms themselves are not created or destroyed in the process.
For example, if we consider the combustion of methane (CH4) with oxygen (O2) to produce carbon dioxide (CO2) and water (H2O), the reactants (methane and oxygen) and the products (carbon dioxide and water) are all made up of the same types of atoms (carbon, hydrogen, and oxygen), but they are rearranged in different ways. The chemical properties of the reactants and products may differ, but they are still related in terms of their atomic and molecular composition.
It's difficult though to say which is more likely between atoms and molecules because they are both essential components of chemical reactions. In a chemical reaction, atoms combine to form molecules or break apart from molecules to form new molecules. Therefore, both atoms and molecules are important in a chemical reaction.
However, if we had to choose one that is more likely to be common between the reactants and products, it would probably be atoms. This is because in most chemical reactions, the atoms involved in the reactants are rearranged to form the products. The chemical reaction simply involves the rearrangement of the atoms, but the atoms themselves are not created or destroyed
On the other hand, molecules may change significantly during a chemical reaction, as they are made up of specific arrangements of atoms. The chemical properties of the reactants and products may also differ because of changes in the molecular structure. Therefore, while molecules are still an essential part of chemical reactions, it is more likely that atoms will be common between the reactants and products.
Which statement best describes the law of conservation of mass?(1 point)
A) Reactants in a chemical reaction rearrange to form a new substance or substances.
Not college level lol
B) Reactants and products cannot escape from a closed system.
C) Matter cannot be created or destroyed in a chemical reaction.
D) Chemical symbols are used to show atom balance before and after a reaction.
Lesson name) Balanced Chemical Equations Quick Check.
A student used a balance and a graduated cylinder to collect the data 10.23,20.0, and 21.5 calclulate the density of the elements
Assuming that the student measured the mass of the elements using a balance and the volume using a graduated cylinder, we can use the following formula to calculate the density:
Density = mass / volume
Let's say the masses of the elements were 10.23 grams, 20.0 grams, and 21.5 grams, and the volumes were 10 mL, 20 mL, and 25 mL respectively.
Then, the densities would be:
Density of element 1 = 10.23 g / 10 mL = 1.023 g/mL
Density of element 2 = 20.0 g / 20 mL = 1.0 g/mL
Density of element 3 = 21.5 g / 25 mL = 0.86 g/mL
What is density?
Density is a physical property of matter that describes how much mass is contained in a given volume of a substance. It is defined as the amount of mass per unit volume, and is typically measured in grams per cubic centimeter (g/cm³) or kilograms per cubic meter (kg/m³).
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help please need by tomorrow
A metal object with mass of 20.9 g is heated to 97.0 ∘C and then transferred to an insulated container containing 86.0 g of water at 20.5 ∘C. The water temperature rises and the temperature of the metal object falls until they both reach the same final temperature of 24.1 ∘C.
What is the specific heat of this metal object? Assume that all the heat lost by the metal object is absorbed by the water.
Answer:
To find the specific heat of the metal object, we can use the equation:
q = mcΔT
where q is the amount of heat transferred, m is the mass of the object, c is the specific heat capacity, and ΔT is the change in temperature.
We know that the metal object loses heat while the water gains heat, and the total amount of heat lost by the metal object is equal to the total amount of heat gained by the water:
qmetal = qwater
Using the equation above for each of these, we get:
mcΔT = mwatercwaterΔTwater
where cwater is the specific heat capacity of water and mwater is the mass of water.
Substituting in the given values, we get:
(20.9 g)(c)(97.0 °C - 24.1 °C) = (86.0 g)(4.184 J/g·°C)(24.1 °C - 20.5 °C)
Simplifying and solving for c, we get:
c = [(86.0 g)(4.184 J/g·°C)(24.1 °C - 20.5 °C)] / [(20.9 g)(97.0 °C - 24.1 °C)]
c = 0.385 J/g·°C
Therefore, the specific heat of the metal object is 0.385 J/g·°C.
After addition of 20.00 mL of 0.500 M standard KOH solution to 10.00 mL of formic acid (HCOOH, Ka = 1.8 × 10-4), the equivalence point is reached. What is the molarity of the formic acid?
What is the pH at the equivalence point, based on the question above? Please make a suggestion for an appropriate indicator.
Answer: 3.79
Explanation: The balanced chemical equation for the reaction between formic acid (HCOOH) and KOH is:
HCOOH + KOH → HCOOK + H2O
We can use the stoichiometry of this reaction to calculate the number of moles of formic acid that reacted with the KOH:
moles of KOH = (20.00 mL)(0.500 mol/L) = 0.01000 moles
moles of HCOOH = moles of KOH
Therefore, the initial number of moles of formic acid is:
moles of HCOOH = (10.00 mL)(x mol/L) = 0.01000 moles
where x is the molarity of formic acid.
Solving for x, we get:
x = 1.00 M
Therefore, the molarity of the formic acid is 1.00 M.
At the equivalence point, all of the formic acid has reacted with the KOH, and the solution contains only the salt formed by the reaction, potassium formate (HCOOK). The pH at the equivalence point can be calculated using the equation for the salt hydrolysis constant:
Kb = Kw/Ka
where Kb is the base dissociation constant of the conjugate base (formate ion), Kw is the ion product constant for water (1.0 × 10^-14 at 25°C), and Ka is the acid dissociation constant of the acid (formic acid). Rearranging this equation, we get:
Kb/Ka = [OH^-][HCOO^-]/[HCOOH]
At the equivalence point, the concentration of the formate ion (HCOO^-) is equal to the concentration of the KOH added (0.01000 moles / 30.00 mL = 0.3333 M). We can assume that the concentration of the hydroxide ion (OH^-) is also equal to 0.3333 M, since KOH is a strong base and will dissociate completely. Substituting these values into the equation above, we get:
Kb/Ka = (0.3333)^2 / [HCOOH]
Solving for [HCOOH], we get:
[HCOOH] = (0.3333)^2 / (1.8 × 10^-4) = 6181.5 M
Taking the negative logarithm of this concentration, we get the pH at the equivalence point:
pH = -log[HCOOH] = -log(6181.5) = 3.79
Therefore, the pH at the equivalence point is 3.79.
Regenerate response
A calorimeter contains 21.0 mL of water at 13.5 ∘C. When 1.70g of X (a substance with a molar mass of 77.0 g/mol) is added, it dissolves via the reaction X(s)+H2O(l)→X(aq) and the temperature of the solution increases to 25.0 ∘C.
Calculate the enthalpy change, ΔH , for this reaction per mole of X.
Assume that the specific heat of the resulting solution is equal to that of water [4.18 J/(g⋅∘C)], that density of water is 1.00 g/mL, and that no heat is lost to the calorimeter itself, nor to the surroundings.
Express the change in enthalpy in kilojoules per mole to three significant figures.
Enthalpy change, H, for this reaction per mole of X is thus equal to 0 J/mol.
How can the water's temperature in the calorimeter be determined?The amount of heat that the calorimeter, q cal, gains may be calculated using the formula qcal = Ccalt, where t is the change in temperature that the mixture experiences.
The equation: can be used to compute the enthalpy change, H. ΔH = q / n
The heat absorbed by the water can be calculated using the equation:
q1 = m1 x c1 x ΔT1
m1 = 21.0 g = 0.0210 kg (since the density of water is 1.00 g/mL)
c1 = 4.18 J/(g⋅∘C)
ΔT1 = 25.0 ∘C - 13.5 ∘C = 11.5 ∘C
q1 = (0.0210 kg) x (4.18 J/(g⋅∘C)) x (11.5 ∘C) = 1.09 J
The heat absorbed by X can be calculated using the equation:
q2 = m2 x ΔHfus
where m2 is the mass of X and ΔHfus is the enthalpy of fusion of X.
m2 = 1.70 g = 0.00170 kg
ΔHfus = ΔH / n = ΔH / (m2/M)
where M is the molar mass of X.
We can rearrange this equation to solve for ΔH: ΔH = q2 x (m2/M)
With this assumption, we can calculate ΔH as follows:
ΔH = q / n = (q1 + q2) / n
ΔH = (1.09 J + q2) / (0.00170 kg / 77.0 g/mol)
ΔH = (1.09 J + q2) / 0.0000221 mol
The fact that the heat absorbed by X is equal to the heat emitted by the solution can be used to solve for q2: q2 = -q1
Therefore, ΔH = (1.09 J - q1) / 0.0000221 mol
Substituting q1, we get:
ΔH = (1.09 J - 1.09 J) / 0.0000221 mol
ΔH = 0 J/mol
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Please help almost due?
Answer:
-lithium
-atomic number
-mass number
-protons
Explanation:
NEED HELP ASAP PLS AND THX PIC IS ATTACHED
Q5. How many atoms of ions are there in 363g of Iron fillings? (Atomic weight of Iron is 55.85 a.m.u) 1.6.71x10²4 atoms 2. 3.91×1024 atoms 3. 0.31x1024 atoms 4. 23.71x10²4 atoms
The solution, which is closest to option 4, is 7.816 x 10²⁴ atoms of ions.
Why are atoms referred to as ions?An atom can generate a positive charge or a negative charge depending on whether the number of electrons in the atom is greater or fewer than the number of protons in the atom. When one atom is drawn to another atom as a result of an imbalance in the numbers of its electrons and protons, it is referred to as an ION.
We must first figure out how many moles of iron there are in 363 g of iron fillings in order to answer this problem. The formula is as follows:
number of moles=mass/molar mass
The molar mass of iron (Fe) is 55.85 g/mol. Therefore:
number of moles of iron = 363 g / 55.85 g/mol = 6.499 mol
363 g of iron fillings have the following amount of iron ions in total:
total number of iron ions = 2 x number of moles of iron
= 2 x 6.499 mol
= 12.998 mol
The number of moles of iron ions can be converted to the overall amount of iron ions using Avogadro's number (6.022 x 10²³ ions/mol) as follows:
total number of iron ions
= 12.998 mol x 6.022 x 10²³ ions/mol
= 7.816 x 10²⁴ ions
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1.Explain the Theory of Plate Tectonics and provide three observations about the earth
that provide evidence to support the theory. Describe how plate tectonics cause
major geological events such as ocean basins, earthquakes, and volcanic eruptions.
Be sure to:
• Use science terms appropriately
.
• Organize and develop your ideas effectively
• Choose your words carefully
.
• Edit your writing for grammar, mechanics, and spelling
The Theory of Plate Tectonics is a scientific theory that explains how the Earth's outer shell is composed of several large plates that move and interact with each other over time.
What is the theory of plate tectonics?Three observations about the Earth that provide evidence to support the Theory of Plate Tectonics are:
Earthquakes: Earthquakes occur when the movement and interaction of the tectonic plates cause rocks to fracture and shift. These seismic events are most common along the boundaries of the tectonic plates, where the movement and interaction are most pronounced. The distribution of earthquakes around the world is consistent with the theory of plate tectonics.
Volcanic Activity: Volcanic activity is closely related to the movement of tectonic plates. Many of the world's most active and well-known volcanoes are located near plate boundaries, where the movement and interaction of plates lead to the formation of magma chambers and the release of volcanic material. This relationship between volcanoes and plate boundaries supports the theory of plate tectonics.
Continental Drift: The theory of plate tectonics also explains the phenomenon of continental drift, which refers to the movement of the Earth's continents over time. According to this theory, the continents are part of the tectonic plates and have moved and shifted over millions of years. The fit of the coastlines of Africa and South America is a well-known example of continental drift and supports the theory of plate tectonics.
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For the following diagram, select all statements that are true. (Picture provided)
According to given Information:
The energy change of the reaction is -20kJ is true statement, This is exothermic reaction.
What is exothermic?Exothermic meaning that the products of the reaction have lower energy than the reactants.
The negative value of the energy change (-20kJ) indicates that energy is released during the reaction.
What is energy change?Energy change refers to the difference in energy between the products and reactants of a chemical reaction. If the energy change is positive, it means that energy is absorbed by the reaction and the reaction is endothermic.
If the energy change is negative, it means the energy is released by the reaction and the reaction is exothermic. The magnitude of the energy change provides information about the amount of energy that is released or absorbed during the reaction
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HELP
A student in today's experiment produces 2.538 g of pure aspirin product. If commercial aspirin pills contain 325 mg of aspirin per pill, how many pills could be manufactured from the student's 2.538 g of product?
Which statement describes gases
according to kinetic molecular theory?
According to the kinetic molecular theory, gases are described by the following statement:
Gases consist of small particles (atoms or molecules) that are in constant random motion.What does the statement meanThis statement highlights that gases are made up of particles that are in constant motion, moving in straight lines until they collide with another particle or the walls of the container.
The motion of gas particles is random, and their energy increases as the temperature of the gas increases. The kinetic molecular theory also suggests that the particles in a gas are far apart from each other and do not attract or repel each other, except during collisions.
Additionally, the kinetic molecular theory states that the pressure of a gas is caused by the collisions of gas particles with the walls of the container. The higher the concentration of gas particles or the faster they are moving, the greater the pressure of the gas.
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For the following chemical reaction:
In the laboratory, a chemist mixed aqueous barium chloride with aqueous potassium oxide which produced solid barium oxide and aqueous potassium chloride
A. Write the complete balanced chemical equation, including phase labels.
B. Identify the type of reaction that has occurred.
C. Identify the indicator that tells you a chemical reaction has occurred.
Answer:
A. The complete balanced chemical equation, including phase labels, for the reaction is:
BaCl2 (aq) + K2O (aq) → BaO (s) + 2KCl (aq)
B. The type of reaction that has occurred is a double displacement or metathesis reaction. In this reaction, the barium cations (Ba2+) and potassium anions (K+) exchange partners, resulting in the formation of solid barium oxide (BaO) and aqueous potassium chloride (KCl).
C. The indicator that tells you a chemical reaction has occurred is the formation of a solid precipitate. In this reaction, the solid barium oxide (BaO) that forms is a clear indication that a chemical reaction has occurred. Additionally, the fact that the reactants are aqueous and the products include both a solid and an aqueous solution also indicates a chemical reaction has taken place.