Chemistry MCQs for PPSC FPSC KKPSC BPSC SPSC NTS Test No. 57

A Compound possess 8% sulphur by mass. The least molecular mass is:

2 g of O₂ at NTP occupies the volume:

7.5 g of a gas occupies 5.6 litres as STP. The gas is:

A). CO

B). NO

C). CO₂

D). N₂O

At STP the density of a gas (mol. wt. = 45) in g/L is:

The number of significant figures in 306.45 and 40440 are respectively:

Express 145.6 L of chlorine in terms of gram moles.

Number of moles of a solute per kilogram of a solvent is called:

Which has maximum number of oxygen atoms?

A). 1 g of O

B).1 g of O₂

C).1 g of O₃

D). All have same number of O-atoms

One mole of CH4 contains:

A). 4.0 g atoms of hydrogen

B). 3.0 g atom of carbon

C).6.02 × 10²³ atoms of hydrogen

D).1.81 × 10₂₃ molecules of CH₄

One mole of a substance present in 1 kg of solvent. The correct statement regarding above solution is:

A breakfast cereal in advertised to contain 110 mg of sodium per 100 g of the cereal. The percent of sodium in the cereal is:

Area of nuclear cross section is measured in ‘Barn’. It is equal to:

A). 10^-28 m²

B). 10^-18 m²

C). 10^-8 m²

D). 10^-34 m²

Which of the following is the odd one with regard to mass?

A). 1 g atom of sulphur

B). 0.5 moles of CO₂

C). 1 mole of O₂

D). 3 × 10²³ molecules of SO₂

If we consider that 1/6, in place of 1/12, mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of a substance will:

Which of the following statement is correct?

A). 1 mole of electrons weighs 5.4 mg

B). 1 mole of electrons weighs 5.4 kg

C). 1 mole of electrons weighs 0.54 mg

D). 1 mole of electrons has 1.6 × 10^-19 C of charge

The incorrect statement for 14 g of CO is:

A). It occupies 2.24 litre at NTP

B).It corresponds to 0.5 mol of CO

C).It corresponds to same mol of CO and N₂

D). It corresponds to 3.01 × 10²³ molecules of CO

Which of the following pairs of gases contain equal number of molecules?

A). CO₂ and NO₂

B). CO and (CN)₂

C). NO and CO

D). N₂O and CO₂

The quantity of PV/K_BT represents the:

The weight of one molecule of a compound C₆0H₁₂₂ is:

A). 1.3 × 10^-20 g

B). 5.01 × 10^-21 g

C). 3.72 × 10²³ g

D). 1.4 × ^10-21 g

The vapour density of ozone is:

Which is the correct order of micro, nano, femto and pico here?

The samples of NaCl are produced when Na combines separately with two isotopes of chlorine Cl³⁵ and Cl³⁷. Which law is illustrated?

50 g of calcium carbonate was completely burnt in air. What is the weight (in grams) of the
residue?

1000 g calcium carbonate solution contains 10 g carbonate. The concentration of solution is:

The maximum number of molecules is present in:

A). 15 L of O₂ gas at STP

B). 10 L of H₂ gas at STP

C). 1.5 g of H₂ gas

D). 5 g of CO₂ gas