Question

In this question it should be assumed that (NH4)2CO3.H2O(s) dissolves in water without causing
an increase in volume.
Which mass of (NH4)2CO3.H2O(s) should be added to 800 cm of water to form a 0.100 mol dm
solution of NH4 ions?
A
4.569
B
7.139
C
9.12g
D
14.3g
the following are options I-a b c or d
pls solve this with showing the working​

Answer 1

Answer:

ans is (B)

Explanation:

Answer 2

Answer:

A

Explanation:

(NH4)2CO3. H20 + H20 = 2NH4^+ + C03^2- +2H20

    n=?            V= 800 cm3    c= 0.100 M

                                              1000 cm3 = 0.1 mol

since volume assumed to remain constant

                                              800 cm3 = 0.1/1000 x 800 =0.08 mol

Mol ratio (NH4)2CO3. H20 : 2NH4^+

                            1       : 2

thus, no. of mol of (NH4)2CO3. H20 = 0.04

Mr (NH4)2CO3. H20 = 28+8+12+48+ 18= 114

mass = n x Mr = 4.56 g