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5/96 MCQs for:

MATTER - PROPERTIES AND TRANSFORMATION: Principles Of Chemistry - Formulae, Moles And Equations

To determine the formula of copper oxide by mass differences, a known mass of copper is heated in air. What is the key measurement taken after heating?

The initial mass of the crucible.

The volume of oxygen consumed.

The mass of the resulting copper oxide.

The temperature change during the reaction.

The relative atomic mass (RAM) of an element is defined as:

(Average mass of one atom of an element) / (1/12 mass of one atom of carbon)

(Average mass of any atom of an element) / (1/12 mass of one atom of carbon-12 )

(Average mass of one atom of an element) / (1/12 mass of one atom of carbon-12 )

( mass of one atom of an element) / (1/12 mass of one atom of carbon-12 )

What is the percentage composition by mass of oxygen in carbon dioxide (CO₂)? (C=12, O=16)

66.7%.

72.7%.

27.3%.

50.0%.

A mole of a substance is defined as __

The amount of the substance that contains the same number of elementary compounds such as atoms, molecules, ions etc, as there are carbon atoms in exactly 12 grams of carbon-12.

The amount of the substance that contains the same number of elementary particles such as atoms, molecules, ions etc, as there are carbon atoms in exactly 12 grams of carbon-12.

The amount of the substance that contains the same number of elementary particles such as atoms, molecules, ions etc, as there are in exactly 12 grams of carbon-12.

The amount of the substance that contains the same number of elementary particles such as atoms, molecules, ions etc, as there are carbon atoms in exactly 12 grams of carbon.

The mass in grams of one mole of a substance is:

Gas constant

Molar mass

Avogadro constant

Mole