Question

= 0.556 mol kg
75 g
Intext Questions
2.1 Calculate the mass percentage of benzene (CH) and carbon tetrachloride
(CC14) if 22 g of benzene is dissolved in 122 g of carbon tetrachloride.
(Ans: 15.28; 84.72)
2.2 Calculate the mole fraction of benzene in solution containing 30% by mass
in carbon tetrachloride. [Ans: 0.4583, 0.541)
2.3 Calculate the molarity of each of the following solutions: (a) 30 g of Co(NO3)2
6H2O in 4.3 L of solution (b) 30 mL of 0.5 M H2SO4 diluted to 500 mL.
[Ans: 0.024M, 0.03M]
2.4 Calculate the mass of urea (NH,CONH2) required in making 2.5 kg of 0.25
molal aqueous solution. [Ans.: 37.5g)
2.5 Calculate (a) molality (b) molarity and (c) mole fraction of KI if the density of
20% (mass/mass) aqueous KI is 1.202 g ml?.
(Ans: 1.51m, 1.45M, 0.0265)
Solubility​

Answer 1

Answer:

0.458

Explanation:

2. 2  ) Let the total mass of the solution be 100 g and the mass of benzene be 30 g.

∴ Mass of carbon tetrachloride = (100 - 30)g = 70 g

Molar mass of benzene (C6H6) = (6 × 12 + 6 × 1) g mol - 1

= 78 g mol - 1

∴ Number of moles of C6H6  =30/78 mol

= 0.3846 mol

Molar mass of carbon tetrachloride (CCl4) = 1 × 12 + 4 × 35.5

= 154 g mol - 1

∴ Number of moles of CCl4 = 70/154 mol

= 0.4545 mol

Thus, the mole fraction of C6H6 is given as:

= 0.3846 / (0.3846 +0.4545)

= 0.458