The amount of heat, in kilojoules, that is required to melt 15 g of ice at 0 degrees Celsius and raise the temperature of the liquid to 85 degrees Celsius is 10.3178 kJ.
Heat changeThe process involves melting of ice at 0 degrees Celsius and then heating the resulting water to a temperature of 85 degrees Celsius.
Solid water is first converted to liquid water without a change in temperature.Liquid water is heated without a change of state to 85 degrees Celsius.Now, let's calculate the heat change of the process:
Heat change (ΔH) = n x heat of fusion) + mcΔt
Where n = number of moles
m = mass = 15 g
c = specific heat capacity of water = 4.81 J/g[tex]^oC[/tex]
heat of fusion = 6010 J/mole
In this case, n = mass/molar mass
= 15/18
= 0.83 moles
ΔH = (0.83 x 6010) + 15 x 4.81 x (85 - 0)
= 10317.8 Joules
But 1000 Joules = 1 kilojoules
Thus, 10317.8 joules = 10.3178 kJ
The kilojoule of heat required to melt the ice and raise the temperature of the resulting water to 85 degrees Celsius is 10.3178 kJ.
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The empirical formula for a compound that contains 6.34 grams carbon and 1.06 grams hydrogen is
Answer:
[tex]CH_2[/tex]Explanation:
Here, we want to get an empirical formula
We start by dividing each of the masses by the corresponding atomic masses
The atomic mass of carbon is 12 amu
The atomic mass of hydrogen is 1 amu
We start the division as follows:
[tex]\begin{gathered} C\text{ = }\frac{6.34}{12}\text{ = 0.5283333} \\ \\ H\text{ = }\frac{1.06}{1}\text{ = 1.06} \end{gathered}[/tex]Now, we divide the results by the smaller of the two:
[tex]\begin{gathered} C\text{ = }\frac{0.528333}{0.529333}\text{ = 1} \\ \\ H\text{ = }\frac{1.06}{0.528333}\text{ = 2} \end{gathered}[/tex]Thus, we have the empirical formula as:
[tex]CH_2[/tex]The polarity of the covalent bond between two given atoms is determined/estimated byGroup of answer choicesOctet RuleElectronegativity differencesNumber of bonds between the atomsSolubility
1) Covalent bond polarity.
To determine the polarity, we use a property called electronegativity. This is a tendency to attract shared electrons in a chemical bond. If the difference in electronegativity is greater than 1.7, the bond is polar. If the difference is less than 1.7, the bond is nonpolar.
What other things can you think of that might be preserved?
Answer:
Bones, teeth, shells, and other hard body parts can be fairly easily preserved as fossils. However, they might become broken, worn, or even dissolved before they are buried by sediment. The soft bodies of organisms, on the other hand, are relatively hard to preserve.
Predict the shape and bond angles of the following molecules:
H2S
CF4
HCN
NF3
BCl3
NH2Cl
OF2
The shape and bond angle of the molecule will be, H2S =shape= bent, Bond angle =less than 109 degrees
2) CH4 = shape = tetrahedral
bond angle-=109 degrees
1)H2S =shape= bent
Bond angle =less than 109 degrees
2) CH4 = shape = tetrahedral
bond angle-=109 degrees
3) HCN = shape = Linear
Bond angle = 180 degrees
4) NF3 = shape = trigonal planar
Bond angle = less than 109 degrees
5) BCl3 = shape = trigonal planar
Bond angle = 120 degrees
6) NH2Cl = shape = trigonal pyramidal
Bond angle = 107 degrees
7) OF2 = shape = linear
Bond angle = 109 degrees
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A 500 g sample of Al2(SO4)3 is reacted with 450 g of Ca(OH)2. A total of 596 g of CasO4 isproduced. What is the limiting reactant in this reaction, and how many moles of excess reactantare unreacted? Al2(SO4)3 (ag) + 3Ca(OH)2 (ag) -> 2Al(OH)3 (s) + 3CaSO4 (s)
ANSWER
[tex]undefined[/tex]EXPLANATION
Given that;
The mass of Al2(SO4)3 is 500 grams
The mass of Ca(OH)2 is 450 grams
The mass of CaSO4 is 596 grams
Follow the steps below to find the limiting reactant of the reaction
Step 1; Write the balanced equation of the reaction
[tex]\text{ Al}_2(SO_4)_{3(aq)}+\text{ 3Ca\lparen OH\rparen}_{2(aq)}\text{ }\rightarrow\text{ 2Al\lparen OH\rparen}_{3(s)}\text{ + 3CaSO}_{4(s)}[/tex]In the reaction above, 1 mole Al2(SO4)3 reacts with 3 moles Ca(OH)2 to give 2 moles Al(OH)3 and 3 moles CaSO4
Step 2; Determine the number of moles using the below formula
[tex]\text{ mole = }\frac{\text{ mass}}{\text{ molar mass}}[/tex]Recall, that the molar mass of Al2(SO4)3 is 342.15 g/mol and the molar mass of Ca(OH)2 is 74.093 g/mol
For Al2(SO4)3
[tex]\begin{gathered} \text{ Mole = }\frac{500}{\text{ 342.15}} \\ \text{ Mole = 1.461 moles} \end{gathered}[/tex]For Ca(OH)2
[tex]\begin{gathered} \text{ Mole = }\frac{\text{ 450}}{\text{ 74.093}} \\ \text{ Mole = 6.073 moles} \end{gathered}[/tex]Step 3; Find the limiting reactant of the reaction
To find the limiting reactant of the reaction, divide the moles of the reactant by the co-efficient of the compound
[tex]\begin{gathered} \text{ For Al}_2(SO_4)_3 \\ \text{ The mole ratio = }\frac{1.461}{1} \\ \text{ The mole ratio = 1.461 mol/wt} \\ \\ \text{ For Ca\lparen OH\rparen}_2 \\ \text{ The mole ratio = }\frac{\text{ 6.073}}{3} \\ \text{ The mole ratio = 2.024 mol/wt} \end{gathered}[/tex]Since the limiting reactant of the reaction is the reactant with the lowest number of mol/wt, then Al2(SO4)3 is the limiting reactant
[tex]\text{ The limiting reactant of the reaction is Al}_2(SO_4)_3[/tex]The excess reactant of the reaction is Ca(OH)2
Therefore, the no of moles of the excess reactant that is unreacted is
6.073 - 1.461 = 4.612 moles
Hence, the number of moles of the excess reactant that is unreacted is 4.621 moles
Dr. Lamar is performing an autopsy on a murder victim. What is he MOST likely to do during this procedure?
A.
Apply a Hematix strip to the fingertips to collect prints.
B.
Use the Kastle-Meyer test to examine blood samples.
C.
Collect hair samples from multiple places on the body.
D.
Scrape away any dried blood present on the body.
Collecting hair samples from multiple places on the body is most likely to be done during an autopsy.
What is Autopsy?This is referred to as a post-mortem examination which is done on a corpse so as to determine the cause of the sickness and for appropriate actions to be taken.
Hair is easily dispersed as a result of light weight and structure and its ability to easily attach to other substances. The hair will be most likely taken during this procedure, it helps to identify the race and sex of the suspect. It can also be used to identify the suspect through DNA analysis which is therefore the reason why option C was chosen as the correct choice.
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Answer: C
Explanation:
How many grams of solute would you use to prepare the following solutions?241.0 mL of 1.11 M NaOHExpress your answer with the appropriate units.
10.7 grams
Explanations:The formula for calculating the molarity of a solution is given as:
[tex]\begin{gathered} molarity=\frac{moles}{volume} \\ moles=molarity\times volume \end{gathered}[/tex]Given the following parameters
molarity of NaOH = 1.11M
volume of solution = 241.0mL = 0.241L
Find the moles of NaOH
[tex]\begin{gathered} moles\text{ of Na}OH=\frac{1.11mol}{L}\times0.241L \\ moles\text{ of Na}OH=0.2675moles \end{gathered}[/tex]Determine the mass of solute (NaOH)
[tex]\begin{gathered} Mass\text{ of NaOH}=mole\times molar\text{ mass} \\ Mass\text{ of NaOH}=0.2675\times40 \\ Mass\text{ of NaOH}=10.7grams \end{gathered}[/tex]Hence the grams of solute that would be used to prepare the solution is 10.7grams
Calculate the pH if [H+] = 2.79 x 10^-11 M
Answer:
10.6.
Explanation:
What is given?
[H⁺] = 2.79 x 10⁻¹¹ M.
Step-by-step solution:
Let's see the formula of pH:
[tex]pH=-\log_{10}[H^+]=-\log_{10}[H_3O^+].[/tex]Where [H⁺] is the proton concentration in M. So we have to replace the given data in the formula:
[tex]pH=-\log_{10}{}\lbrack2.79\cdot10^{-11}]=10.55\approx10.6.[/tex]The pH of a [H⁺] = 2.79 x 10⁻¹¹ M solution would be 10.6.
What is the electronic configuration of argon
Electronic configuration: this shows us the distribution of electrons in an atom. The chart below helps us find the electron configuration.
How many protons does argon have?
Argon has 18 protons.
The electronc configuration of argon is 1s2 2s2 2p6 3s2 3p6
Leslie incorrectly balances an equation as 2C4H10 + 12O2 → 8CO2 + 10H2O.Which coefficient should she change?281012
Answer: 13 O2 instead of 12 O2
Explanation:
A gas occupies a constant volume at 35.0 celsius and 97 kPa. What is the pressure of the gas when the temperature is increased to 75 celsius?
For this question we are going to use Gay-Lussac's Law, which is an experimental gas law that shows the relationship between temperature and pressure in a gas. The formula is:
P1/T1 = P2/T2
We have:
P1 = 97 kPa
T1 = 308 K, we need to use Kelvin
P2 = ?
T2 = 348 K
Now we add these values into the formula:
97/308 = P2/348
0.315 = P2/348
P2 = 109.6 kPa, this will be new pressure
Calculate the percent by volume of 75 mL of concentrated juice if the juice is diluted with 200 mL of water.
The percent by volume is 27.27%
At a pressure of 1.00atm the solubility of nitrogen in water is 23.5mg gas/100g water. Indicate whether each of the following changes would increase or decrease the solubility of nitrogen in water
Solubility of a substance changes as the pressure changes. If the pressure is high, solubility increases. When pressure is low, solubility decreases.
At 1 atm the solubility of Nitrogen in water is 23.5 mg gas/110g water.
The solution is submerged 40 m under water. Solubility increase.
The solution is carried to the top of a mountain. Solubility decrease.
The solution is placed in a chamber where the pressure is 0.50 atm. Solubility decrease.
The solution is brought into outer space. Solubility decrease.
The solution is canned at a pressure of 2.04 atm. Solubility increase.
Suppose 2.68 g of barium acetate is dissolved in 300. mL of a 45.0 m Maqueous solution of ammonium sulfate.
Calculate the final molarity of acetate anion in the solution. You can assume the volume of the solution doesn't change when the barium
acetate is dissolved in it.
Round your answer to 3 significant digits.
Explanation
Final Molarity of acetate ion is 0.0394 M. The number of moles of solute per liter of solution is referred to as molarity.
What is Molarity?The amount of a substance in a given volume of solution is measured in molarity (M). Molarity is defined as the number of moles of a solute in one liter of solution. A solution's molarity is also known as its molar concentration.
Therefore,
We first assume that the reaction completes and that the volume of the reaction remains constant.
The balanced stoichiometric equation is as follows:
Ba(CH₃COO)₂ + (NH₄)₂SO₄ → BaSO₄ + 2NH₄(CH₃COO)
First, we must determine which reactant is in excess and which has been completely consumed by the reaction. To do so, we count the number of moles of each reactant at the beginning of the reaction.
For Ba(CH₃COO)₂
The number of moles = (Mass)/(Molar Mass)
Barium acetate mass = 2.68 g
Barium acetate molar mass = 255.43 g/mol
The number of moles = (2.68/255.43) = 0.0104 moles.
For (NH₄)₂SO₄,
Number of moles = (Concentration in mol/L) × (Volume in L)
Concentration of Ammonium surface in mol/L = 45 M
Volume in L = (300/1000) = 0.3 L
Number of moles = 45 × 0.3 = 13.5 moles
From the stoichiometric balance of the reaction,
1 mole of Ba(CH₃COO)₂ responds with 1 mole of (NH₄)₂SO₄
As a result, it is clear that Ba(CH₃COO)₂ is the limiting reagent; the chemical specie that is depleted during the reaction and determines the number of other reactants and products formed.
1 mole of Ba(CH₃COO)₂ provide 2 moles of NH₄(CH₃COO)
0.0591 moles of Ba(CH₃COO)₂ will give 2 × 0.0591 moles of NH₄(CH₃COO); 0.1182 moles of NH₄(CH₃COO).
The molarity of NH₄(CH₃COO) exist then provide as (number of moles) ÷ (Vol in L)
The number of moles = 0.1182 moles
L volume of the solution = 0.3 L
Molarity of NH₄(CH₃COO) = (0.01182/0.3)
= 0.0394 M
Note that 1 mole of NH₄(CH₃COO) contains 1 mole of acetate ion,
Hence, 0.0394 M of NH₄(CH₃COO) also contains 0.0394 M of acetate ion.
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10. When a metal atom combines with a nonmetal
atom, the nonmetal atom will
A. lose electrons and decrease in size
B. lose electrons and increase in size
C. gain electrons and decrease in size
D. gain electrons and increase in size
When a metal atom combines with a nonmetal atom, the nonmetal atom will gain electrons and decrease in size
What happen when metal react with non metal ?In a reaction between metals and non-metals, electrons are moved from the metal atoms to the non-metal atoms, resulting in the formation of ions. An ionic compound is the name given to the resulting substance.
Ions are created when metals and non-metals interact because the metal atoms' electrons are transferred to the non-metal atoms.The end result of this procedure is an ionic compound. Metal atoms provide their electrons to non-metal atoms. Metal atoms change into positive ions, whereas non-metal atoms change into negative ions.Learn more about Metals and non metal here:
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4. Collaborate with a partner, make a brochure that highlights an example of a
technology that you have seen in which density is important.
The common use of density in ships and submarines is to predict whether or not a thing will float. Objects that have densities lower than those of water will sink if their densities are lower than water's.
What does density mean ?A product's density is a measure of how heavy it is relation to its size. If added to water, an object will float if its density is less than that of the water, while it will sink if its higher density. The density of a material is a distinguishing quality that is independent of the substance's volume.
Why is density important in chemistry?Because density is an intense property, it remains constant regardless of how much of a substance is present. Because it enables us to predict which compounds will float and which will sink in a liquid, density is a crucial notion.
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Is NH4OH soluble or insoluble in water
Answer:
Ammonium hydroxide. Ammonium hydroxide is an inorganic herbicide, fungicide and microbiocide.It is non-volatile and highly soluble in water.
Explanation:
According to the concept of solubility, ammonium hydroxide is insoluble in water.
What is solubility?Solubility is defined as the ability of a substance which is basically solute to form a solution with another substance. There is an extent to which a substance is soluble in a particular solvent. This is generally measured as the concentration of a solute present in a saturated solution.
The solubility mainly depends on the composition of solute and solvent ,its pH and presence of other dissolved substance. It is also dependent on temperature and pressure which is maintained.Concept of solubility is not valid for chemical reactions which are irreversible. The dependency of solubility on various factors is due to interactions between the particles, molecule or ions.
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Which quantum state (n,ℓ,mℓ) is NOT possible? and why
2,0,0
3,1,-1
3,0,1
3,2,2
16,14,15
The quantum numbers that are not possible are 16,14,15.
What are quantum numbers?The quantum numbers are used to address the position of the electron in an atom. They are the set of numbers that show the most probable position of the electron in an atom. There are four sets of quantum numbers that describe the position of an electron and they are;
1) Principal quantum number
2) Orbital quantum number
3) Magnetic quantum number
4) Spin quantum number.
The set of quantum numbers 16,14,15 is not possible because ml must have values of -l to +l as we know.
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How many milliliters of a 2.59 M H2SO4 solution are needed to neutralize 47.50 mL of a 0.827 M KOH solution?
Given Data:
Concentration of acid, H2SO4 = 2.59 M
For, H2SO4, n-factor = 2, i.e., the number of [tex]H^{+}[/tex] ions on dissociation
Thus, the concentration in normality, N1 = 2.59 x 2 = 5.18 N
Concentration of base, KOH = 0.827 M
For, KOH, n-factor = 1, i.e., the number of [tex]OH^{-}[/tex] ions on dissociation
Thus, the concentration in normality, N2 = 0.827 x 1 = 0.827 N
Volume of base, V2 = 47.50 mL
Using the formula, N1 x V1 = N2 x V2, where, V1 = volume of acid
Thus, volume of acid required to neutralize, V1 = [tex]\frac{N_{2}X V_{2} }{N_{1} }[/tex] = [tex]\frac{0.827 X 47.50}{5.18}[/tex]
= 7.58 mL.
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4 Fe + 3 O2 = 2 Fe2O3How many grams of oxygen (O2) do you needto produce 75 g Fe203?
Answer
mass of oxygen = 22.54 g
Explanation
Given:
4 Fe + 3 O2 = 2 Fe2O3
Mass of Fe203 = 75 g
Required: Mass of O2
We know:
Molar mass of Fe2O3 = 159,69 g/mol
Molar mass of O2 = 31.998 g/mol
Solution:
Step 1: Calculate the moles of Fe2O3
n = m/M where n is the moles, m is the mass and M is the molar mass
n = 75g/159,69 g/mol
n = 0.469 mol
Step 2: Use the stoichiometry to find the moles of O2
The molar ratio between Fe2O3 and O2 is 2:3
Therefore moles of O2 = 0.469 mol x (3/2) = 0.704 mol
Step 3: Find the mass of O2
m = n x M
m = 0.704 mol x 31.998 g/mol
m = 22.54 g
A cheeseburger from a fast food restaurant contains 19 g of fat, 20 g of carbohydrates and 28 g of protein. How many kcal of energy does the cheeseburger contain? (Food caloric values are 9.0 kcal/g for fats, 4.0 kcal/g for carbohydrates and 4.0kcal/g for protein). Round the answer for each type of food to the nearest tens place. A. 70. kcal B. 360 calories C. 17 calories D. 630 calories
Answer:
Example:
Here, we want to get the kcal of energy contained in the cheeseburger
To do this, we multiply the caloric values of each food type by their masses and then sum
Mathematically, we have that as:
[tex]19(9)\text{ + 20\lparen4\rparen + 28\lparen4\rparen = 363 kcal}[/tex]To the nearest tens, we have that as 360 kcal
Which statement describes the hydrogen bonds in an ethanol molecule? (image attached)thank you :)
Answer
Only the hydrogen atom attached to the oxygen atom is capable of forming hydrogen bonds. A dipole does not form between the hydrogen and the carbon atoms.
Explanation
The description of the hydrogen bonds in an ethanol molecule is that hydrogen bonding can occur between ethanol molecules, although not as effectively as in water. The hydrogen bonding is limited by the fact that there is only one hydrogen in each ethanol molecule with a sufficient δ+ charge.
Therefore only the hydrogen atom attached to the oxygen atom is capable of forming hydrogen bonds. A dipole does not form between the hydrogen and the carbon atoms.
The second option is the correct answer.
Why are chemical reactions used in the agricultural industry. Please cite all your sources.
Answer:
The objective of agricultural chemistry is to preserve or improve the fertility of soil, increase the agricultural yield and improve the quality of the crop. To reach those objectives the agricultural industry uses two types of chemicals.
- Fertilizers: increase soil fertility making crops more productive. They usually are compounds that contain three basic elements: P, K and N.
- Pesticides: control weeds (herbicides), insects (insecticides) and diseases from fungus (fungicides).
C2H4 + 3O2 ——> 2CO2 + H2OWhat volume of oxygen at STP is needed to react with 5.75 mol of C2H4 (Show all work and data charts)
Explanation:
C₂H₄ + 3 O₂ ——> 2 CO₂ + H₂O
According to the coefficients of the equation 1 mol of C₂H₄ will react with 3 moles of O₂. Then, the molar ratio between C₂H₄ and O₂ is 1 to 3. We can use that relationship to find the number of moles of oxygen that are needed to react with 5.75 moles of C₂H₄.
1 mol of C₂H₄ = 3 moles of O₂
moles of O₂ = 5.75 moles of C₂H₄ * 3 moles of O₂/(1 mol of C₂H₄)
moles of O₂ = 17.25 moles
One mol of a gas at STP always occupies 22.4 L. We can use that relationship to find the volume of oxygen.
1 mol of O₂ = 22.4 L
volume = 17.25 moles of O₂ * 22.4 L/(1 mol of O₂)
volume = 386.4 L
Answer: 386.4 L at STP is needed to react.
The molecular formula of Allicin, The compound responsible for the characteristics smell of garlic, is C6H 10 OS2. A) what is the molar mass of a Allicin?B) how many moles of allicin are present in 4.20 mg of the substance?C) how many molecules of Allicin are in 4.20 mg of the substance?D) how many C atoms are present in 4.20 mg of allicin?
1) Molar mass of Allicin.
1.1- Write the formula.
[tex]C_6H_{10}OS_2[/tex]1.2- Look for the molar mass of each element in the formula.
C: 12.011 g/mol
H: 1.008 g/mol
O: 15.999 g/mol
S: 32.06 g/mol
1.3- Count how many atoms are there in the formula.
C: 6
H: 10
O: 1
S: 2
1.4- Set the equation.
[tex]TheMolarMass=(6*C)+(10*H)+(1*O)+(2*S)[/tex]Plug in the known values.
[tex]TheMolarMass=(6*12.011\text{ }g/mol)+(10*1.008\text{ }g/mol)+(1*15.999\text{ }g/mol)+(2*32.06\text{ }g/mol)[/tex][tex]MM=72.066\text{ }g/mol+10.08\text{ }g/mol+15.999\text{ }g/mol+64.12\text{ }g/mol[/tex][tex]MM=162.265\text{ }g/mol[/tex]The molar mass (MM) of Allicin (C6H10OS2) is 162.265 g/mol.
2) Moles of Allicin in the sample.
Allicin sample: 4.20 mg
The molar mass of Allicin (C6H10OS2) is 162.265 g/mol.
2.1- Convert mg to g.
1g = 1000 mg
[tex]g=4.20\text{ }mg*\frac{1\text{ }g}{1000\text{ }mg}=0.00420\text{ }g[/tex]2.2- Convert grams to moles.
The molar mass of Allicin (C6H10OS2) is 162.265 g/mol.
Allicin sample: 0.00420 g
[tex]mol\text{ }C_6H_{10}OS_2=0.00420\text{ }g\text{ }C_6H_{10}OS_2*\frac{1\text{ }mol\text{ }C_6H_{10}OS_2}{162.265\text{ }g\text{ }C_6H_{10}OS_2}=0.00002588\text{ }mol\text{ }C_6H_{10}OS_2[/tex]There are 0.00002588 moles of Allicin (C6H10OS2) in 4.20 mg of substance.
The result can also be expressed as 2.588*10^(-5) mol.
3) Molecules of Allicin in the sample.
The Avogadro's number is 6.022*10^(23).
1 mol C6H10OS2 = 6.022*10^(23) molecules C6H10OS2
Allicin sample: 0.00002588 mol.
[tex]molecules\text{ }of\text{ }C_6H_{10}OS_2=0.00002588\text{ }mol\text{ }C_6H_{10}OS_2*\frac{6.022*10^{23}\text{ }molecules}{1\text{ }mol\text{ }C_6H_{10}OS_2}=1.558*10^{19}\text{ }molecules\text{ }of\text{ }C_6H_{10}OS_2[/tex]There are 1.558*10^(19) molecules in the sample.
4) C atoms in the sample of Allicin.
The ratio of carbon in one molecule of Allicin is 6 C atoms: 1 molecule of Allicin.
Allicin sample: 1.558*10^(19) molecules C6H10OS2.
[tex]C\text{ }atoms=1.588*10^{19}\text{ }molecules*\frac{6\text{ }C\text{ }atoms}{1\text{ }molecule\text{ }C_6H_{10}OS_2}=9.35*10^{19}\text{ }C\text{ }atoms.[/tex]There are 9.35*10^(19) C atoms in the sample.
Balance the following equation:ZnO(s)⟶ΔZn(l)+O2(g) Express your answer as a chemical equation. Identify all of the phases in your answer.
Answer:2ZnO(s)→2Zn(l)+O2(g)
Explanation:
Question 16 of 25According to the Gibbs free energy equation, AG = AH-TAS, when is areaction always spontaneous?A. When AH and AS are both positiveB. When AH is negative and AS is positiveC. When AH is positive and AS is negativeD. When AH and AS are both negativeSUBMIT
Answer
B. When ΔH is negative and ΔS is positive
Explanation
The spontaneity of a reaction can be determined by the sign of the Gibbs free energy change. For a spontaneous reaction, the change in Gibbs free energy should be negative, that is:
[tex]\Delta G=\Delta H-T\Delta S[/tex]The spontaneity of a process can depend on the temperature. Since the temperature value here corresponds to the absolute temperature, this implies that T > 0 for any T. Therefore, to have a negative difference for any temperature value, the change in enthalpy (ΔH), should be negative and the change in entropy (ΔS) should be positive so that we always subtract a positive number from a negative number. This corresponds to a negative value in ΔG.
Hence, the
3.0 x 10 ^23 atoms of calcium to moles
Answer:
[tex]0.5\text{ mole}[/tex]Explanation:
Here, we want to get the number of moles
Mathematically:
[tex]1\text{ mole has 6.02 }\times\text{ 10}^{23}\text{ atoms}[/tex]The number of moles in the question would be:
[tex]\frac{3.0\times10^{23}\text{ atoms}}{1}\times\frac{1\text{ mole}}{6.02\times10^{23}\text{ atoms}}\text{ = 0.5 mole}[/tex]1. How would an element be classified?a. homogeneous mixtureb. pure substancec. solutiond. heterogeneous mixture
Hello
To solve this question, we should understand that an element is is the base form in which a particule exit. However, it can either be in a molecule, atom or in a compound. Elements are pure substance which form up the molecule, atom or compounds. An element can said to be an identity of a substance. Elements are generally classified using the periodic table into metals, non-metals, metalliods.
In this question, the most possibe defination is that an element is a pure substance
A homogenous mixture is a mixture that is said to have one phase of substance throughout. I.e the comprising substance are all in a single phase.
A solution is the mixture of a solute that is completely dissolved in a solvent.
A heterogeneous mixture is a solution that the substance are not in a single phase.
The answer to this question is option B
Cobalt(II) chloride reacts with fluorine in a single replacement reaction to produce cobalt(II) fluoride and chlorine gas. How many grams of fluorine are required to produce 124.13 g of cobalt(II)fluoride?
The balanced equation of the reaction is:
CoCl2 + F2 → CoF2 + Cl2
Now, we will follow the next steps to solve the question.
1. We find the moles present in 124.13 g of cobalt(II)fluoride (CoF2) using the molar molar mass of CoF2. The molar mass of CoF2 is: 96.93g/mol
2. By stoichiometry we find the moles of fluorine (F2) needed. Since the ratio CoF2 to F2 is 1, the moles will be the same as those produced from cobalt(II)fluoride.
3. We find the grams of fluorine by multiplying the moles by the molar mass of fluorine. The molar mass of fluorine is 38.00 g/mol
Let's proceed with the calculations:
1. Moles of CoF2
[tex]\begin{gathered} molCoF_2=givengCoF_2\times\frac{1molCoF_2}{MolarMass,gCoF_2} \\ molCoF_2=124.13gCoF_2\times\frac{1molCoF_2}{96.93gCoF_2}=1.28molCoF_2 \end{gathered}[/tex]2. Moles of F2
[tex]molF_2=1.28molCoF_2\times\frac{1molF_2}{1molCoF_2}=1.28molF_2[/tex]3. Grams of F2
[tex]\begin{gathered} gF_2=givenmolF_2\times\frac{MolarMass,gF_2}{1molF_2} \\ gF_2=1.28molF_2\times\frac{38.00gF_2}{1molF_2}=48.66gF_2 \end{gathered}[/tex]Answer: To produce 124.13 grams of cobalt(II)fluoride are required 48.66grams of fluorine