**Directions for 1 to 4 :** are based on the graph given below:

**Question 1. ** Which of the following salts has greatest solubility?

(a) A at 800C.

(b) B at 350 C.

(c) C at 390 C.

(d) D at 850 C.

**Question 2. ** Approximately, how many kg of C can be dissolved in 10 liters of water at 300C?

(a) 0.04

(b) 0.4

(c) 4

(d) 0.35

**Question 3.** By what % is the solubility of A in water increased as the water is heated from 300C to 800 C?

(a) 100

(b) 200

(c) 250

(d) 167

**Question 4.** If 1 mole of B weighs 0.07456 kg, approximately. How many moles of B can be dissolved in 100 liters of water at 360C?

(a) 700

(b) 650

(c) 480

(d) 540

**Question 5.** Which of the salts has greater change in solubility in kg / liter of water between 150C and 250C?

(a) D

(b) B

(c) E

(d) F

### Answers and Explanations

After observing the given line graph, we can make the following deductions;

**Answer 1. (C)**

Hence (c) is the correct answer.

**Answer 2. (C)**

The solubility of C in one litter at 30^{0}C = 0.38 kg
Therefore solubility of C in 10 lt. would be = 3.8 kg., Approx = 4 kg.
Therefore the right answer is option (c)

**Answer 3. (D)**

Solubility of A at 30c is .15 while at 80c it is .4 The increase in % of solubility of A = (0.4 – 0.15) 100/0.15 = 167%.

**Answer 4. (D)**

The Solubility of B at 36^{o}C = 0.4 kg./lt.
Therefore in 100 lt. the amount of B that can be dissolved = 40 kg.
Number of moles = 40 / 0.075 = 533.
Therefore approx. 540 moles can be dissolved in 100 lt. of water at 36^{o}C.

**Answer 5. (C)**

The solubility of F, B, Dis almost constant as we see the graph between 15^{o}C &25^{o}C.
Also, it can also be seen from graph that solubility of E is maximum.