Answer:
= 82%
Explanation:
Percentage purity is calculated by the formula;
% purity = (mass of pure chemical/total mass of sample) × 100
In this case;
1 mole of Ca(NO3)2 = 164 g
but; 164 g of Ca(NO3)2 = 40 g Ca
Therefore; mass of Ca(NO3)2 = 164 /40
= 4.1 g
Thus;
% purity of Ca(NO3)2 = (Mass of Ca(NO3)2/ mass of the sample)× 100
= (4.1 g/ 5 g) × 100
= 82%
