Question

0.7 g of `Na_(2)CO_(3).xH_(2)O` was dissolved in water to make 100 mL solution, 20 mL of this solution required 19.8 mL of 0.1 N HCl for complete neutralisation. The value of x is :
A. 5
B. 2
C. 3
D. 4

Answer 1

Correct Answer - B

Answer 2

 Correct answer is (B)

 \(N_1V_1=N_2V_2\)

\(N_1\times20mL=0.1\times19.8mL\)

\(N_1=0.099N\)

\(\therefore\) \(0.099N=\frac{0.7\times2\times1000}{(106+x18)\times100}\)

\(106+x18=\frac{14}{0.099}\)

\(106+x18=141.4\)

\(x18=35.4\)

\(x\approx2.\)