Free MCQs & Online Quiz Practice for Exams

Q: The mass of an atom (element) compared with the mass of one atom of C-12 is called

A) One mole

B) Gram atomic mass

C) Atomic number

D) Relative atomic mass

Q: Which of the following is not true for a mole?

A) It is a counting unit

B) It is the gram atomic or gram formula mass of a substance

C) It contains 6.023×10²³ particles

D) It contains different number of particles for different substances

Q: What is the mass (in grams) of 5 moles of water (H₂O)?

A) 90 g

B) 36 g

C) 18 g

D) 100 g

Q: The number of molecules in 22 g of CO₂ is

A) 6.023×10²³

B) 3.011×10²³

C) 6.023×10²¹

D) 6.023×10²²

Q: What will be the values of temperature and pressure at standard condition (STP)?

A) 100°C, 1 atm

B) 298 K, 1 atm

C) 273 K, 760 mm Hg

D) 0°C, 760 cm Hg

Q: The molar volume of SO₂ gas at STP is

A) 64 dm³

B) 24 dm³

C) 22.4 dm³

D) 22.4 cm³

Q: The percentage of Ca in CaCO₃ is

A) 12%

B) 10%

C) 48%

D) 40%

Q: A limiting reactant is one

A) Which is present in maximum amount

B) Which produces minimum number of moles of product

C) Which produces maximum number of moles of product

D) Does not affect the amount of product

Q: Efficiency of a chemical reaction can be checked by calculating

A) Amount of limiting reactant

B) Amount of excess reactant

C) Amount of the Products formed

D) Amount of the reactant unused

Q: Actual yield will reach the ideal (theoretical) value if the % yield of the reaction is

A) 105%

B) 50%

C) 90%

D) 100%

Q: The maximum number of moles are present in:

A) 11.2 dm³ of H₂ gas at STP

B) 44.8 dm³ of N₂ gas at STP

C) 67.2 dm³ of CO₂ gas at STP

D) 22.4 dm³ of O₂ gas at STP

Q: The e/m ratio of cathode rays is

A) 1.76×10²³ C/kg

B) 1.76×10¹¹ C/kg

C) 1.76×10³¹ C/kg

D) 1.76×10⁻? C/kg

Q: The wave number (ṽ) of a radiation with λ = 2 ×10⁸ nm will be

A) 0.5×10⁻⁸ nm⁻¹

B) 10 nm⁻¹

C) 5 nm⁻¹

D) 100 nm⁻¹

Q: For an electron in K-shell, the correct four quantum numbers are represented by

A) n=1, l=0, m=0, s=+₋½

B) n=2, l=0, m=0, s=+½

C) n=1, l=1, m=0, s=+½

D) n=2, l=2, m=+2, s=+½

Q: All are electromagnetic in nature except

A) IR rays

B) X-Rays

C) UV rays

D) Cathode rays

Q: The energy associated with a quantum of radiation is

A) hν

B) nh/2π

C) 2hν

D) 1/2hν

Q: Bohr's theory cannot be applied on

A) H

B) H⁺¹

C) He⁺¹

D) Li⁺²

Q: Which of the following sets of quantum numbers are not possible?

A) n=3, l=2, m=0, s=−½

B) n=3, l=3, m=−3, s=+½

C) n=4, l=3, m=−3, s=+½

D) n=3, l=1, m=0, s=−½

Q: The frequency of a green light is 6×10¹⁴ Hz; its wavelength is

A) 5nm

B) 500nm

C) 5000nm

D) 100nm

Q: Which of the following sub-shells do not exist?

A) 1p

B) 5d

C) 6f

D) 1s