Quantities in Chemistry Part 2

A hydrocarbon contains 85.7 % carbon by mass. What is the empirical formula of the hydrocarbon?

• C₂H₃

• CH₂

• C₂H₅

• CH₃

What is the sum of all coefficients for the combustion of one mole of propane?

• 8

• 12

• 13

• 15

The structural formula of a dioxin is shown below (C₁₂H₈O₂).

What is its empirical formula?

• C₆O

• C₆H₄O

• C₆H₆O

• C₁₂H₈O₂

• 160

• 178

• 186

• 250

For which compounds is the empirical formula the same as the molecular formula?

I. Methane (CH₄)

II. Ethene (C₂H₄)

III. Ethanol (C₂H₅OH)

• I and II only

• I and III only

• II and III only

• I, II and III

What are the coefficients of H₂SO₄ and H₃PO₄ when the following equation is balanced using the smallest possible whole numbers?

• 1 H₂SO₄ and 2 H₃PO₄

• 2 H₂SO₄ and 3 H₃PO₄

• 3 H₂SO₄ and 1 H₃PO₄

• 3 H₂SO₄ and 2 H₃PO₄

Which statements are correct about Avogadro’s constant?

I. It is the number of ions in 12 g of sodium hydride, NaH.

II. It is 6.022 x 10²³

III. It is the number of atoms in 12 g of ¹²C.

• I and II only

• I and III only

• II and III only

• I, II and III

What mass of carbon dioxide, CO₂(g), in g, is produced when 5.0 g of calcium carbonate, CaCO₃(s), reacts completely with hydrochloric acid, HCl(aq)?

• 0.050

• 2.2

• 4.4

• 5.0

What is the number of ions in 0.20 mol of (NH₄)₃PO₄

• 8.0 x 10^-1

• 1.2 x 10²³

• 4.8 x 10²³

• 2.4 x 10²⁴

What mass of carbon dioxide, in g, is produced by the complete reduction of 80 g of iron(III) oxide?

• 44

• 66

• 88

• 132