9M Unit 1 MCQ's

Which one of the following compounds can be separated by physical means?

• mixture

• element

• compound

• radical

The most abundant element occurring in the oceans is:

• oxygen

• hydrogen

• nitrogen

• silicon

Which one of the following elements are found in most abundance in the Earth's crust?

• oxygen

• aluminium

• silicon

• iron

The third abundant gas found in the Earth's atmosphere is

• oxygen

• carbon monooxide

• nitrogen

• argon

The third abundant gas found in the Earth's atmosphere is

• 1.66 × 10 ^-24 mg

• 1.66 × 10 ^-24 g

• 1.66 × 10 ^-24 kg

• 1.66 × 10 ^-23 g

Which one of the following molecule is not tri-atomic?

• H₂

• O₃

• H O

• CO₂

The mass of one molecule of water is:

• 18 amu

• 18 g

• 18 mg

• 18 kg

The molar mass of H₂ SO₄ is

• 98 g

• 98 amu

• 98 mg

• 98 kg

Which one of the following is a molecular mass of O₂ in amu?

• 32 amu

• 53.12 × 10^{-24 amu}

• 1.92 × 10^{-25 amu}

• 192.64 × 10^{-25 amu}

The valency of the noble gases is:

• 3

• 0

• 2

• 1