Question

(b) Calculate the molecular mass of the following:
(i) Na2SO4-10H20 (ii) (NH4)2CO3​

Answer 1

Answer:Na2SO4 . 10H2O

Na = 23g , S = 32g , O = 16g , H = 1g

Na2 ==> 23×2 = 46g

SO4 ==> 32 + 16×4 = 96g

10H2O ==> 10×2×1 + 10×16 ==> 180g

Molecular weight = 46 + 96 + 180

==> 322g

(NH4)2CO3

N = 14g , H = 1g , C = 12g , O = 16g

(NH4)2 ==> (14 + 4×1) × 2 = 36g

CO3 ==> 12 + 16×3 ==> 12 + 48 = 60g

Molecular weight = 36 + 60

==> 96g

Answer 2

Answer:

1) 322 g/mol

2) 96 g/mol

Explanation:

1) [2(23) + 1(32) + 4(16)] + 10[2(1) + 1(16) ]

= 322g/mol

2) [2{1(14) +4(1)} + 1(12) + 3(16) ]

= 96g/mol