This method of quantitative determination of percent purity is titrimetric reactions. These reactions most commonly involve neutralization reactions between an acid and a base. Then, we look at the neutralization reaction:
H₂C₂O₄ + 2 NaOH ⇒ Na₂C₂O₄ + 2 H₂O
So, we do the stoichiometric calculations. The important data we should know is the molar mass of oxalic acid which is equal to 90 g/mol.
(0.2283 mol/L NaOH * 0.3798 L * 1 mol H₂C₂O₄/ 2mol NaOH * 90 g/mol H₂C₂O₄) ÷ 0.7984 g *100%
= 488%
This is impossible. The purity can't be more than 100%. Looking at our calculations and the balance reaction, all steps were done correctly. So, I think there is some typographical error in the given. The mass of the sample should be 7.984 g. Then, the answer would be 48.87% purity.
<u>Answer:</u> The mass percent of hydrogen in methyl acetate is 8 %
<u>Explanation:</u>
The given chemical formula of methyl acetate is 
To calculate the mass percentage of hydrogen in methyl acetate, we use the equation:

Mass of hydrogen = (6 × 1) = 6 g
Mass of methyl acetate = [(3 × 12) + (6 × 1) + (2 × 16)] = 74 g
Putting values in above equation, we get:

Hence, the mass percent of hydrogen in methyl acetate is 8 %
Answer:
As water on the surface of lakes, oceans, and rivers warms up, it travels into the sky as very tiny droplets, or vapor. When the water vapor gets colder, it turns back to liquid to help form clouds.
When the liquid gets so heavy it can’t stay in the atmosphere anymore, it falls, or “precipitates,” as rain, snow, sleet, hail, or, my favorite, graupel. Once the precipitation reaches the ground or lands in lakes, oceans, and rivers, the cycle continues.
Explanation:
The molecular formula for aspartame is C14H18N2O5, and its molar mass is about 294 g/mol.
Convert 1.2 g into moles, which gives
1.2 g / 294 g/mol = 4.08 X 10-3 moles aspartame.
Since each mole of aspartame has 2 moles of nitrogen, you have 8.16 X 10-3 moles of N in your 1.2 grams of aspartame.
Finally, multiply that by Avogadro's number to get the number of N atoms:
8.16 X 10^-3 mol X 6.02 X 10^23 = 4.9 X 10^21 nitrogen atoms.
The answer is D because it is a chemical reaction, but the mass is “lost” because a solid becomes a gas, which leaves the container.