The mole fraction of ethylene glycol (C2H6O2) in a solution containing 20% of C2H6O2 by mass is:
1. 0.932
2. 0.0672
3. 0.832
4. 0.732
The molarity of a solution containing 5 g of NaOH in 450 mL solution is:
1. 0.188 mol dm–3
2. 0.478 mol dm–3
3. 0.378 mol dm–3
4. 0.278 mol dm–3
The molality of 2.5 g of ethanoic acid (CH3COOH) in 75 g of benzene is:
1. 0.656 mol kg–1
2. 0.616 mol kg–1
3. 0.556 mol kg–1
4. 0.456 mol kg–1
If N2 gas is bubbled through water at 293 K, how many millimoles of N2 gas would dissolve in 1 litre of water?
(Partial pressure of nitrogen = 0.987 bar, Henry’s law constant for N2 at 293 K = 76.48 kbar).
1. 0.716 mmol
2. 0.616 mmol
3. 0.726 mmol
4. 0.516 mmol
The vapour pressure of pure benzene at a certain temperature is 0.850 bar. A non-volatile, non-electrolyte solid weighing 0.5 g is added to 39.0 g of benzene (molar mass 78 g mol–1). Vapour pressure of the solution, then, is 0.845 bar. The molar mass of the solid substance is:
1. | 150 g mol–1
|
2. | 180 g mol–1
|
3. | 170 g mol–1
|
4. | 160 g mol–1 |
18 g of glucose, C6H12O6, is dissolved in 1 kg of water in a saucepan. The temperature at which water boil at 1.013 bar is-
(Kb for water is 0.52 K kg mol-1)
1. 383.202 K
2. 373.202 K
3. 363.202 K
4. 393.202 K
The boiling point of benzene is 353.23 K. When 1.80 g of a non-volatile solute was dissolved in 90 g of benzene, the boiling point is raised to 354.11 K. The molar mass of the solute is:
Kb for benzene is 2.53 K kg mol–1
1. 55 g mol–1
2. 64 g mol–1
3. 58 g mol–1
4. 68 g mol–1
45 g of ethylene glycol (C2H6O2) is mixed with 600 g of water. The freezing point of the solution is:
1. 268.15 K
2. 270.95 K
3. 272.75 K
4. 267.15 K
1.00 g of a non-electrolyte solute dissolved in 50 g of benzene lowered the freezing point of benzene by 0.40 K. The freezing point depression constant of benzene is 5.12 K kg mol–1. The molar mass of the solute is:
1. | 245 g mol–1 |
2. | 256 g mol–1 |
3. | 264 g mol–1 |
4. | 274 g mol–1 |
200 cm3 of an aqueous solution of a protein contains 1.26 g of the protein. The osmotic pressure of such a solution at 300 K is found to be 2.57 × 10–3 bar. The molar mass of the protein is:
1. | 61,022 g mol–1 |
2. | 65,042 g mol–1 |
3. | 68,012 g mol–1 |
4. | 57,012 g mol–1 |