Chemistry NCERT Exemplar Solutions Class 12th Chapter Sixteen

A. $\underset{Salt}{N{a}_{2}C{O}_3}+\underset{di\mathcal{l}}{H_{2}S{O}_4}\to NaS{O}_4+H_{2}O+C{O}_2\uparrow$            

CO₂ is colourless gas with brisk effervescence and turns lime water milky

$C{O}_2+Ca{\left(OH\right)}_2\to CaC{O}_3\downarrow +H_{2}O$                              

B. $\underset{Salt}{N{a}_{2}S}+\underset{di\mathcal{l}}{H_{2}S{O}_4}\to N{a}_{2}S{O}_4+H_{2}S\uparrow$            

H₂S + (CH₃COO)₂Pb → $\underset{Black}{PbS}+2C{H}_{3}COOH$  

C. $\underset{Salt}{N{a}_{2}S{O}_3}+\underset{di\mathcal{l}}{H_{2}S{O}_4}\to N{a}_{2}S{O}_4+H_{2}O+S{O}_3\uparrow$            

SO₃ is colourless gas which turns acidified potassium dichromate solution green as

$S{O}_3+KMn{O}_4+H^{+}\to \underset{Green}{MnS{O}_4}+S{O}_4^{2-}+H_{2}O$                             

D. $\underset{Salt}{2NaN{O}_2}+\underset{di\mathcal{l}}{H_{2}S{O}_4}\to N{a}_{2}S{O}_4+2HN{O}_2$          

$3HN{O}_2\to NH{O}_3+2NO+H_{2}O$                              

$2NO+O_2\to \underset{Browngas}{2N{O}_2}$                              

$2HN{O}_2+2Kl+2C{H}_{3}COOH\to 2C{H}_{3}COOK+2H_{2}O+2NO+I_2$                             

I₂ + starch → Blue colour complex.

This is a long answer type question as classified in NCERT Exemplar

Enzyme inhibitors block the binding site of enzyme and prevent the binding of substrate and then inhibit the catalytic activity of enzyme. They act in two different ways.

(i) Drugs which compete with substrate for their attachment on the active sites of enzymes are called competitive inhibitor.

(ii) Some drugs bind to a different site of enzyme called allosteric site. It changes the shape of the active site and substrate cannot recognize it. Such enzymes are called non-competitive inhibitor the bond formed between enzyme and an inhibitor is strong covalent bond then enzyme is blocked permanently.