Question

an experiment is carried out to determine the formula of an oxide of mercury. the oxide is a red solid. it decomposed into its elements when heated at room temperature and pressure (r.t.p.). // mass of oxide of mercury: 2.16g // volume of oxygen collected at r.t.p.: 120cm³ // what is the mass of mercury produced?

Answer 1

Answer:

Mass of mercury produced = 2.00 g

Explanation:

At room temperature and pressure, the temperature T = 25° C or 298.15 K while the pressure = 1 atmosphere or 760 mmHg.

Mass of oxide of mercury decomposed at room temperature and pressure = 2.16 g

Volume of oxygen produced = 120 cm³ or 0.12 dm³

One mole of any gas has a volume of 24 dm³ at room temperature and pressure.

Therefore, number of moles of oxygen produced = 0.12 dm³ / 24 dm³/mol = 0.005 moles

Mass of oxygen produced = number of moles × molar mass

Molar mass of oxygen = 32 g/mol

Mass of oxygen produced = 0.005 moles × 32 g/mol = 0.16 g

Thus, mass of mercury produced = mass of mercury oxide decomposed - mass of oxygen produced

Mass of mercury produced = 2.16 g - 0.16 g

Mass of mercury produced = 2.00 g