PART - 1 CH - 2 Structure of Atom — Chemistry STD 11 Science — Question

1. State Henry's Law.
2. Assign reason for the following:

1. A solution of NH₄Cl in water shows pH less than 7.
2. In qualitative analysis NH₄Cl is added before adding NH₄OH for testing Fe³⁺ or AP³⁺ ions.

3. Consider the reaction:

$\text{N}_2(\text{g})+3\text{H}_2(\text{g})\rightleftharpoons2\text{NH}_3+\text{Heat}$

Indicate the direction in which the equilibrium will shift when:

1. Temperature is increased.
2. Pressure is increased.

1. CO₂ and SO₂ are not isostructural.
2. BF₃ and NF₃ are not isostructural.
3. $\text{BH}^-_4$ and $\text{NH}^+_4$ are isostructural.
4. N₂ has higher bond order than NO.
5. In NO⁺ and N₂, the bond order is same.

1. Hydrolysis of sucrose give

$\text{Sucrose}+\text{H}_2\text{O}\rightleftharpoons\text{Glucose}+\text{Fructose}$

Equilibrium constant K_c for the reaction is 2 × 10¹³ at 300K. Calculate $\Delta\text{G}^\circ\text{ at }300\text{K.}(\log 2=0.3010)$

2. The concentration of hydrogen in two sample of soft drinks A and B 4.0 × 10^-7 and 3.2 × 10^-6 respectively. Which of these two soft drinks has higher pH?

1. Predict the acidic, basic or neutral nature of the following salts:

NaCN, KBr, NaNO₂, NH₄NO₃

2. What is the minimum volume of water required to dissolve 1 g of calcium sulphate at 298K? (For calcium sulphate K_sp is 9.1 × 10^-6).
3. At 450K ; K_p = 2.0 × 10¹⁰bar^-1 for the reaction at equilibrium:

​​​​​​​​​​​​​​$2\text{SO}_2(\text{g})+\text{O}_2(\text{g})\rightleftharpoons2\text{SO}_3(\text{g})$

What is K_c at this temperature?