Question

Which of the following will form negatively charged colloidal solution?

• A. $100$ ml $0.1$M $AgN{O}_3+100$ ml $0.1$ M KI
• B. $100$ ml $0.2$M $AgN{O}_3+100$ ml $0.1$M KI
• C. $100$ml $0.1$M $AgN{O}_3+100$ ml $0.2$ M KI
• D. $100$ ml $0.2$M $AgN{O}_3+200$ ml $0.1$M KI

Answer 1

The correct option is C $100$ml $0.1$M $AgN{O}_3+100$ ml $0.2$ M KI

milli moles of $AgN{O}_3=100\times 0.1=10$

milli moles of $KI=100\times .02=20$

$KI$ is in excess.

$AgI$ will be precipitated and excess $KI$ as $I^{-}$ ions will surround $AgI$ and form negative charged colloid.

Therefore, correct option is C.