Concentration Unit

What is molality?

• no of mole of solute in 1 liter of solution
• no of mole of solute in 1 kg of solvent

Total number of mol fraction for all component in the solution is equal to

• 1.0
• 0.95
• 0.50
• 2.0

Calculate mol fraction of H₂O in 1.33 molal NaOH solution.

• 0.56
• 0.76
• 0.98
• 0.84

What is the molarity of 4.0 g of NaCl (Molar mass=58.45) in 3800 mL of solution?

• 0.018 M

• 0.001M

• 1.052 M

• 0.062 M

Calculate the mole fraction of benzene (C₆H₆) in a solution of 46.8 g benzene and 36.8 g of toluene (C₇H₈). [Molar mass benzene = 78; Molar mass toluene = 92]

• 0.4

• 0.6

• 0.7

• 0.5

What is the concentration of NaOH in a solution made by mixing 25.0 mL of 0.1 M NaOH with 100 mL of 0.2 M NaOH?

• 0.18 M
• 12.5 M
• 1.25 M
• 0.125 M

The molarity of a solution prepared by dissolving 45.0 g of glucose (C₆H₁₂O₆) in 71.0 mL of water is

[Molar mass glucose = 180]

• 0.0352 M

• 3.52 M

• 0.352 M

• 35.2 M

How many grams of chloride ions are there in 100 mL of 1.90 M aqueous solution of sodium chloride?

• 13.5 g
• 6.74 g
• 0.67 g
• 1.35 g

50.0 mL of phosphoric acid is titrated with 25.0 mL 0.1 M sodium hydroxide solution. The reaction is as follows :
H₃PO₄ + 3NaOH → Na₃PO₄ + 3H₂O
Calculate the molarity of H₃PO₄ acid.

• 0.017 M
• 0.67 M
• 1.5 M
• 6.0 M

How much water need to prepare 200 mL of 0.1 M NaCl from 2.0 M NaCl solution?

• 10 mL
• 200 mL
• 190 mL
• 50 mL