What is the molarity of a solution containing 5 moles of NaCl in 2 liters of solution?
A
2.5 M B
0.4 M C
5 M D
10 M
Analysis & Theory
Molarity (M) = moles of solute / liters of solution = 5 / 2 = 2.5 M.
How is molality defined?
A
Moles of solute per liter of solution B
Moles of solute per kg of solvent C
Moles of solute per gram of solvent D
Moles of solvent per kg of solute
Analysis & Theory
Molality = moles of solute / kilograms of solvent.
A solution contains 10g of KCl (Molar mass = 74.5 g/mol) in 100g of water. What is the molality?
A
1.34 m B
1.00 m C
0.75 m D
2.00 m
Analysis & Theory
Moles of KCl = 10/74.5 = 0.134, Molality = 0.134 / 0.1 = 1.34 m.
Which of the following affects molarity but not molality?
A
Temperature B
Molecular weight C
Pressure D
Type of solute
Analysis & Theory
Molarity depends on volume, which changes with temperature; molality is mass-based and remains unaffected.
What is the normality of 0.5 M H2SO4?
A
0.25 N B
0.5 N C
1 N D
2 N
Analysis & Theory
H2SO4 gives 2 H+ ions, so normality = molarity × n = 0.5 × 2 = 1 N.
Which of the following correctly defines normality?
A
Moles of solute per liter B
Equivalents of solute per kg solvent C
Equivalents of solute per liter of solution D
Moles of solvent per liter
Analysis & Theory
Normality = gram equivalents of solute / liter of solution.
What is the molarity of a 36 g HCl (Molar mass = 36.5 g/mol) in 1 L of solution?
A
1 M B
0.5 M C
2 M D
5 M
Analysis & Theory
Moles = 36 / 36.5 ≈ 0.986, Molarity ≈ 0.986 M ≈ 1 M.
Which is true about molality?
A
Changes with temperature B
Depends on volume of solution C
Does not change with temperature D
Always equal to molarity
Analysis & Theory
Molality is based on mass of solvent, so it is temperature-independent.
If 0.1 mol of NaOH is dissolved in 100 mL of solution, what is the normality?
A
0.1 N B
1 N C
0.5 N D
2 N
Analysis & Theory
Normality = n × molarity = 1 × (0.1 mol / 0.1 L) = 1 N.
Which one is unitless among the following?
A
Molarity B
Molality C
Normality D
None
Analysis & Theory
All of them have units: M (mol/L), m (mol/kg), N (eq/L).