Question

$0.59g$ of the silver salt of an organic acid (molar mass = 210) on ignition gave $0.36g$ of pure silver. The basicity of the acid is:

• A. $3$
• B. $2$
• C. $1$
• D. $4$
• E. $5$

Answer 1

The correct option is A $3$

$\underset{Acid}{H_n}\times \underset{AgN{O}_3}{\overset{N{H}_3}{\to }}\underset{Agsalt}{Agn}\times \stackrel{\Delta }{\to }\underset{Ag}{nAg}$

$\underset{W_{19}}{M-n\times 1+n\times 108}$

$n\times \frac{w_1}{m-n\times 1+n\times 108}\frac{W}{108}g$

Given:

$W_1=0.59g$

$W_2=0.36g$

$m=210$

$M=\frac{n\times w_1\times 108}{w_2}-107n$

$210=\frac{n\times 0.59\times 108}{0.36}-107n$

$\therefore 210=177n-107n$

$\therefore n=3--optionA$