Explore topic-wise MCQs in Chemistry.

This section includes 19 Mcqs, each offering curated multiple-choice questions to sharpen your Chemistry knowledge and support exam preparation. Choose a topic below to get started.

1.

Which of the following may be the most appropriate unit of expressing lead concentrations in drinking water?

A. mg
B. mmole
C. ppm
D. ppb
Answer» E.
Discussion
2.

What is the concentration, in ppm, if 0.025 g of KCl is dissolved in 100 grams of water?

A. 4 x 10<sup>3</sup> ppm
B. 250 ppm
C. 2.5 x 10<sup>-4</sup> ppm
D. 2.5 ppm
Answer» C. 2.5 x 10<sup>-4</sup> ppm
Discussion
3.

What does the unit mmole/kg represent?

A. Molarity
B. Molality
C. Molar mass
D. Milli-molarity
Answer» C. Molar mass
Discussion
4.

What is the number of moles in 650 mL of 98% (v/v) sulfuric acid solution if density of sulfuric acid is 1.83 g/cm3?

A. 63.7
B. 11.9
C. 6.5
D. 11.6
Answer» C. 6.5
Discussion
5.

If 2 L, 4 L and 6 L of three separate solutions of concentrations 1 M, 2 M and 3 M, respectively, are mixed together then what is the concentration of the resultant mixture?

A. 2.333 M
B. 6.000 M
C. 3.333 M
D. 1.500 M
Answer» B. 6.000 M
Discussion
6.

What is a solution called when the concentration of the solute equals its solubility in the solvent?

A. Dilute
B. Saturated
C. Unsaturated
D. Supersaturated
Answer» C. Unsaturated
Discussion
7.

What is the molarity of 20% (w/v) H2SO4 solution?

A. 0.51 M
B. 1.02 M
C. 4.08 M
D. 2.04 M
Answer» E.
Discussion
8.

What is the molality of a solution formed when 58.5g of NaCl is dissolved in 2000 mL of water?

A. 29.2500 m
B. 0.5000 m
C. 0.0005 m
D. 0.2925 m
Answer» C. 0.0005 m
Discussion
9.

What symbol is used to denote molality ?

A. M
B. m
C. mM
D. n
Answer» C. mM
Discussion
10.

Which of the following concentration determine techniques gives a more accurate value?

A. Molarity
B. Molality
C. Formality
D. Normality
Answer» C. Formality
Discussion
11.

Calculate the mole fraction of A if 25g of it is dissolved in 50 moles of B. Given the molar mass of A is 25 g/mole.

A. 0.0196
B. 0.5000
C. 0.3333
D. 0.9259
Answer» B. 0.5000
Discussion
12.

Calculate the volume (mL) of concentrated acid required to prepare 500 mL of 0.25 N HCl solution from concentrated stock HCl solution (specific gravity = 1.19) and 37.2% (by mass).

A. 12.128 mL
B. 20.613 mL
C. 10.307 mL
D. 24.256 mL
Answer» D. 24.256 mL
Discussion
13.

What is the molarity of a 15 ml, 2 M aqueous solution when 285 ml of water is added to it?

A. 0.400 M
B. 0.100 M
C. 0.111 M
D. 0.105 M
Answer» C. 0.111 M
Discussion
14.

What is the molality of a dilute aqueous 0.02 N H3PO4 solution?

A. 0.0050
B. 0.0200
C. 0.00330
D. 0.0067
Answer» E.
Discussion
15.

Consider 100 ml of 0.3 molar solution formed by dissolving 3.33g of XCl2 in water. What is the molar mass of element X? (Atomic mass of Cl = 35.5)

A. 9
B. 24
C. 40
D. 87
Answer» D. 87
Discussion
16.

Iron (III) oxide chunks contain 80 ppm silica (SiO2). What is the concentration of this impurity in mass%?

A. 0.008%
B. 0.080%
C. 0.800%
D. 8.000%
Answer» B. 0.080%
Discussion
17.

If a urea (NH2CONH2) contains 45% (by mass) N2, what is the actual urea content in the sample?

A. 103.7 kg
B. 96.4 kg
C. 9.65 kg
D. 10.4 kg
Answer» C. 9.65 kg
Discussion
18.

What is the mole fraction of glycerin C3H5(OH)3 in a solution containing 33g of glycerin, 60g isopropyl alcohol and rest water?

A. 0.359
B. 0.258
C. 0.205
D. 0.480
Answer» D. 0.480
Discussion
19.

What is the normality of lead (II) nitrate if the density of its 26% (w/w) aqueous solution is 3.105 g/mL? Take molar mass of lead (II) nitrate to be 331g/mol.

A. 2.437 N
B. 4.878 N
C. 0.243 N
D. 0.488 N
Answer» C. 0.243 N
Discussion