(A) 2 mol NH⊕4≡1 mol of (NH4)2CO3=96 g
0.4 mol NH⊕4=96×0.42=19.2 g
Thus, 19.2 g of (NH4)2CO3 (Mw =96 g/mol) contains 0.4 mol NH⊕4.
(B) 8 mol H atoms ≡1 mol (NH4)2CO3=96 g
1 mol H atoms (6.02×1023 H atoms) =968=12.0 g
Thus, the mass of (NH4)2CO3 which contains 6.02×1023 hydrogen atoms is 12.0 g.
(C) (NH4)2CO31mol+2 HCl→2 NH4Cl+CO21mol+H2O
1 mol of CO2≡ 1 mol of (NH4)2CO3=96 g
3 mol of CO2≡96 ×3=288.0 g
Thus, the mass of (NH4)2CO3 which will produce 3.0 mL of CO2 when treated with sufficient acid is 288.0 g.
(D) 100 mL ×0.2 M=20 mmol (NH4)2CO3
=20×10−3×93=1.92 g
Thus, the mass of (NH4)2CO3 required to prepare 100 mL of 0.2 M (NH4)2CO3 solution is 1.92 g.