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.
Answer:
Explanation:
Percent composition is percentage by the mass of element present in the compound.
The formula for chromium(III) nitrate is 
Molar mass of chromium(III) nitrate = 238.011 g/mol
1 mole of chromium(III) nitrate contains 9 moles of oxygen
Molar mass of oxygen = 16 g/mol
So, Mass= Molar mass*Moles = 16*9 g = 144 g
Following reaction is involved in present system:
2KMnO4 + 5H2O2 + 3H2SO4 → 2MnSO4 + K2SO4 + 5O2 + 8H2O
From the above balance reaction, it can be seen that 2 moles of KMnO4 is consumed for every 5 moles of H2O2.
Now, percent by mass of hydrogen peroxide in the original solution can be estimated as follows:
percent by mass =

∴percent by mass =

= 4 %
Your answer would be a change in odor! Hope this helps! ;D
In 1 mole of
, there are 3 moles of ions, 1 mole of Ca^{2+} and 2 mole of
.

Molar mass of
is 110.98 g/mol. Calculating number of moles from given mass as follows:

Thus, number of moles of ions will be
.
Since, 1 mole of any substance has
units of that substance where
is Avogadro's number.
Thus, 9.38 mol of ions will have
number of ions.
Therefore, total number of ions in 347 g of
is
.