A molecule is essentially created by a collection of atoms linked by a network of bonds.
Which of the following best represents a chemical change?
A. Chopping wood
B. Silver tarnishing (changing color)
C. Grape kool-aid mix dissolving in water
D. Dry ice turning into a gas (sublimation- a change of state)
B. silver tarnishing
To calculate the atomic mass of an element, the percent
abundance of etch isotope is needed. ?
Answer:
List the known and unknown quantities and plan the problem. Change each percent abundance into decimal form by dividing by 100. Multiply this value by the atomic mass of that isotope. Add together for each isotope to get the average atomic mass
Explanation:
What is the total pressure exerted by a mixture containing two gases if the partial pressure of one gas is 70 kPa and the partial pressure of the other gas is 30 kPa?
Answer:
The total pressure of a mixture of gases can be defined as the sum of the pressures of each individual gas: Ptotal=P1+P2+… +Pn. + P n . The partial pressure of an individual gas is equal to the total pressure multiplied by the mole fraction of that gas.
Explanation:
hope this helps have a wonderfull day!
need help with question please ..
-20 points
Answer:
B oklolol
[tex][tex]\purple{\rule{45pt}{7pt}}\purple{\rule{45pt}{999999pt}}[tex][/tex]
As an electron in an atom moves from a higher energy state to a lower energy state, the atom
A
becomes a negative ion
В.
becomes a positive ion
С.
releases energy
D.
absorbs energy
Answer:B
Explanation:
What is the mass of an aluminum block if the density of aluminum is 2.70
g/cm and the volume of that block is 4.8 cm?
Answer: 50 M
Explanation:
Mass
Density×Volume2.7(4.8)11.6111.6gFormula used
Density=Mass/VolumeDescribe echolocation. Give an example of an animal that uses echolocation.
dolphin and whales use echolocation
A sample of CO2 gas at 100 degrees Celsius has a volume of 250 mL at 760 mm Hg. How many moles of CO2 are present
There are 8.16 × 10-³ moles of CO2 gas at 100°C with a volume of 250 mL at 760 mm Hg.
HOW TO CALCULATE NUMBER OF MOLES:
The number of moles of a sample of gas can be calculated using the following formula:
PV = nRT
Where;
P = pressure of gas (atm)V = volume (L)n = number of moles (mol)R = gas law constant (0.0821 Latm/molK)T = temperature (K)According to this question;
P = 760mmHg = 1 atmT = 100°C = 100 + 273 = 373KV = 250mL = 0.250Ln = ?1 × 0.250 = n × 0.0821 × 373
0.250 = 30.62n
n = 0.250 ÷ 30.62
n = 8.16 × 10-³mol
Therefore, there are 8.16 × 10-³ moles of CO2 gas at 100°C with a volume of 250 mL at 760 mm Hg.
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How many grams of N2 are required to react with 4.2 moles of Mg in the following process?
3 Mg + N2 → Mg3N2? (Mg = 24.3 g/mol, N = 14.0 g/mol)
Answer:
x = 0.45*28/3 = 4.2 g
Explanation:
showing work
N2 = 28 g/mole
3Mg + N2 → Mg3N2
3moles .. 28 g
0.45 moles .. x
x = 0.45*28/3 = 4.2 g (answer)
What is black powder made of? (Please provide percentage composition of elements as well) Will give brainliest
Answer:
Black powder has 3 main ingredients: Sulfur ([tex]S[/tex]), charcoal ([tex]C_{7}H_{4}O[/tex]), and potassium nitrate ([tex]KNO_{3}[/tex]).
Charcoal is basically just burnt wood and potassium nitrate can easily be displaced.
Keep in mind that this is BLACK POWDER and not actual gunpowder. The difference between the both is significant since gunpowder has a lot more refining processes it has to go through to be actually used in firearms and such.
The percentage composition of black powder should be 75% Potassium Nitrate, 10% Sulfur, and 15% charcoal.
Should be noted that black powder is not a safe compound to deal with, as static friction could ignite it.
There are other alternatives to Black powder such as nitroglycerin (used in dynamites) which is way more powerful and useful in doing mines and exploration but is an extremely tricky and reactive substance to work with.
I do hope this is just for educational purposes because you need to be certified to even just experiment with this (and there are laws to synthesize such as well, which I won't take any responsibility for)
Answer:
sulfur, charcoal and potassium nitrate
Explanation:
Payback
I NEED HELP WItH THIS 5th GRADE QUESTION ITS VERY VERY EASY no Links PLZ and I will Report any useless AWnser PLZ HELP WILL mARK AS BRAINLIST AND Will giVE 1000 Points if correct Answer
How is the mass of a solid measured?
By estimating
With a beaker
With a ruler
With a scale
Answer:
A Beaker or graduated cylinder
Explanation:
Place the solid into the graduated cylinder. Measure the amount of water in the graduated cylinder. The product is the solid's mass wich i mean by that is what number the water level is at.
Answer:
Beaker
Explanation:
If 3.5 mols of P2O3 are formed, how many
moles of P4 reacted?
P2 is 3.5 for p4= 2p2 i.e 2*3.5=7
Answer;561gp203 are required to
produce 10.2 mol H3p03
Can someone help? Thank you.
that' the answer i don't need an explanation
An aqueous solution was prepared by dissolving 266.07 g of AgNO3 ( 169.88 g/mol) in enough water to make a total volume of 250.0 ml. What is the molarity of the solution
Answer:
The correct answer is 6.265 M.
Explanation:
To find the molarity of the solution, we first must recall that molarity represents the number of moles of solute divided by the number of liters of solution. Thus, our first step should be to convert the solute amount in grams to moles, using the given molar mass.
266.07 g * (1 mol/169.88 g) = 1.5662 mol
Now, we can find the molarity using the following formula:
Molarity = moles solute/liters solution
M = 1.5662 mol/0.25 L
M = 6.265 M
Therefore, the molarity of the solution is 6.265 M.
Hope this helps!
what is the chemistry of super glue
cyanoacrylate
When cyanoacrylate polymerizes, the cyanoacrylate sticks together on an atomic level, and it becomes solid. Super Glue solidifies in all the microscopic crevices of an object that it moved into when it was a liquid, and it can form chemical bonds with any anions in the object.
Sulfuric acid reacts with sodium carbonate to form water, a salt, and a gas. Write the formulas for the salt and other compound that are formed in the reaction.
Answer:
H2So4 + Na2Co3 -> H20 + Na2So4 + CO2
The chemical formulas for the salt and other compound that are formed in the reaction are Na₂SO₄,H₂O and CO₂.
What is chemical formula?Chemical formula is a way of representing the number of atoms present in a compound or molecule.It is written with the help of symbols of elements. It also makes use of brackets and subscripts.
Subscripts are used to denote number of atoms of each element and brackets indicate presence of group of atoms. Chemical formula does not contain words. Chemical formula in the simplest form is called empirical formula.
It is not the same as structural formula and does not have any information regarding structure.It does not provide any information regarding structure of molecule as obtained in structural formula.
There are four types of chemical formula:
1)empirical formula
2) structural formula
3)condensed formula
4)molecular formula
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how do you Calculate the molarity of 250 ml of solution in which 2.7 g of MgCl2 are dissolved
Answer:
Molar mass of MgCl2 is 95 g/mol
Mg = 24 g/mol and Cl = 35.5 ×2 = 71 g/mol
moles = mass given/ molar mass
= 2.7/95 = 0.028 mol
volume = 250/1000 = 0.25 dm3 (ml is the same as dm3)
molarity of MgCl2 = moles/volume
= 0.028/0.25
= 0.112 mol/dm3
A student reads that sodium atoms (Na) react with chlorine (Cl2) molecules to form the compound sodium chloride (NaCl). Which model should the student make to satisfy the Law of Conservation of Matter for the formation of sodium chloride, in simplest form?
Answer:
c
Explanation:
Law of Conservation of Matter for the formation of sodium chloride, in simplest form would be obeyed when 2 moles of sodium react with 1 ,mole of chlorine to form 2 moles of sodium chloride.
What is law of conservation of matter?According to law of conservation of matter, it is evident that matter is neither created nor destroyed rather it is restored at the end of a chemical reaction .
Law of conservation of matter and energy are related as matter has mass and mass and energy are directly proportional which is indicated by the equation E=mc².Concept of conservation of matter is widely used in field of chemistry, fluid dynamics.
Law needs to be modified in accordance with laws of quantum mechanics under the principle of mass and energy equivalence.This law was proposed by Antoine Lavoisier in the year 1789.
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patient requires blood transfusion. what is the next thing to do? discuss
ghjguygyughyyhghygyuguyg
50 PTS!!!!!
What type of chemical reaction is Aerobic Cellular Respiration?
Answer: During aerobic respiration, catabolic reactions convert larger complex organic molecules into ATP, the chemical that drives most physiological processes in the body.
Explanation:
Would you expect a Boron (B) atom with atomic mass = 9.999 to be stable?
The balance of forces allows to find the result for the question if the isotope of boron 9.99 una is stable:
The boron isotope of mass 9.99 uma is unstable because the repulsive force increases.The stability of atomic nuclei depends on the balance the force is electrostatic repulsion between the protons and the strong interaction of attraction.
One way to achieve this balance is to increase the separation of the protons with uncharged particles between them, the neutral ones, the strong interaction is of the same magnitude for protons and neutrons, therefore the repulsion is decreased and the strong attraction interaction is maintained. .
In the case of Boron, which has 5 protons, the stable structures have more atomistic 10 and 11 una, which is why it has 5 and 6 neutrons each. Therefore each proton has a neutrons next to it and in the other case a proton at the end has two neutrons, this causes the distance between the protons to increase, decreasing the electrostatic repulsion.
It indicates that we have a Boron nucleus of mass 9.999. The number of protons must remain fixed, therefore there are only 4 neutrons.
Consequently, some of the protons does not have a neutron next to it and can approach the other proton, therefore the electrostatic repulsion increases and the stability of the atom decreases.
In conclusion, using the balance of Forces we can find the result for the question if the isotope of boron 9.99 una is stable:
The boron isotope of mass 9.99 amu is unstable because the repulsive force increases.Learn more about nuclear stability here: https://brainly.com/question/897383
(Please someone help me!) (No links!)
Please ignore the blue dot, I accidentally pressed it and won't get rid of it!
Answer:
you picked the right one the net worth of force would be 10
Explanation:
how cuz you got 1 team with 6 force then aother 1 with 4 add em up u get 10
which planet is closests to the moon
Answer:
Earth
Explanation:
Answer:
Earth
Explanation:
Hope this helps! Pls give brainliest! Also, please sub to Kgirl633 on yt.
It takes 120 mL of 0.15 M of carbonic acid (H2CO3) to neutralize 300 mL of sodium hydroxide (NaOH) for the following balanced chemical reaction:
2NaOH + H2CO3 → N2CO3 + 2NaOH
The concentration of the sodium hydroxide _____.
calculate the mass percentage of each element in aluminum oxide.Then calculate themass of aluminum in a 3.62 gram sample of of aluminum
1. The mass percentage of each element in aluminum oxide Al₂O₃ are:
i. The mass percent of Al in Al₂O₃ is 52.9%
ii. The mass percent of O in Al₂O₃ is 47.1%
2. The mass of Al in 3.62 g of Al₂O₃ is 1.73 g
1i. Determination of the percentage of Al
Molar mass of Al₂O₃ = (2×27) + (3×16) = 102 g/mol Mass of Al of Al₂O₃ = 2 × 27 = 54 gPercentage of Al =?Percentage = mass / mass of sample × 100
Percentage of Al = (54 / 102) × 100
Percentage of Al = 52.9%
1ii. Determination of the percentage of O
Molar mass of Al₂O₃ = 102 g/mol Mass of O of Al₂O₃ = 3 × 16 = 48 gPercentage of O =?Percentage = mass / mass of sample × 100
Percentage of O = (48 / 102) × 100
Percentage of O = 47.1%
2. Determination of the mass of Al in 3.62 g of Al₂O₃.
102 g of Al₂O₃ contains 54 g of Al.
Therefore,
3.62 g of Al₂O₃ will contain = (3.62 × 54) / 102 = 1.73 g of Al.
Thus, 1.73 g of Al is present in 3.62 g of Al₂O₃.
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If 2.5 moles of PA react completely, how many
moles of P203 are formed?
Answer:
For every 2 moles of Na used, 2 moles of NaCl are produced.
Explanation:
Which of the following is not part of an amino acid?
A. ammonium group
B. carboxylate group
C. ether group
D. unique "R" group
Answer:
C
Explanation:
Ether group does not exist in amino acids
Ammonium group is on one side
the carboxylate group is opposite to the ammonium group
the R group defines what amino acid it is.
1. List the ketose carbon(s) that is(are) reduced with NaBH4.
Answer:
ehh im nit sure but here!
Explanation:
When the radiation isn't quite strong
enough to kill right away a terrible
Condition follows what is it called
and what is happening.