Which of the following is the correct word equation for the reaction described below?
mercury(ii) oxide breaks down when it is heated to form oxygen gas and liquid mercury.

a)oxygen gas + mercury → mercury(ii) oxide

b)mercury(ii) oxide + oxygen → mercury

c)mercury → mercury(ii) oxide + oxygen

d)mercury(ii) oxide → oxygen + mercury

Answer is: D) mercury(II) oxide → oxygen + mercury.

Balanced chemical reaction: 2HgO(s) → 2Hg(l) + O₂(g).

This is example of chemical decomposition.

Chemical decomposition is the separation of a single chemical compound (in this example mercury(II) oxide) into its two or more simpler compounds (in this example mercury and oxygen).

44.45 g of tetrahydrofuran.

Explanation:

From the question given above, the following data were obtained:

Volume of tetrahydrofuran = 50 mL

Density of tetrahydrofuran = 0.889 g/mL

Mass of tetrahydrofuran =?

Density of a substance is simply defined as the mass of the substance per unit volume of the substance. Mathematically, density is expressed as shown below:

Density = mass / volume

With the above formula, we shall determine the mass of tetrahydrofuran needed. This can be obtained as follow:

Volume of tetrahydrofuran = 50 mL

Density of tetrahydrofuran = 0.889 g/mL

Mass of tetrahydrofuran =?

Density = mass / volume

0.889 = mass / 50

Cross multiply

Mass = 0.889 × 50

Mass of tetrahydrofuran = 44.45 g

Therefore, the student should weigh out 44.45 g of tetrahydrofuran.