Question

(a) Explain, with example, how the physical states of the reactants and products can be shown in a chemical equation.
(b) Balance the following equation and add state symbols
Zn + HCl → ZnCl2 + H2
(c) Convey the following information in the form of a balanced chemical equation
An aqueous solution of ferrous sulphate reacts with an aqueous solution of sodium hydroxide to form a precipitate of ferrous hydroxide and sodium sulphate remains in solution.""

Answer 1

Answer:

(a) The physical states of the products and the reactants can be represented using them mentioned in the brackets.

i.e., Solid→(s)

liquids→(l)

gases→(g)

Aqueous→(aq)

Precipitate→(ppt.)

(b) Zn(s) +2HCl(aq)→ZnCl₂(aq)+H₂(g)

(c) FeSO₄(aq)+2NaOH(aq)→Fe(OH)₂(ppt.)+Na₂SO₄(aq)

Answer 2

Explanation:

(a) Physical state in chemical reaction:

• The state of the reactants and products are defined with the (s) if it is solid; (cr) if it is crystal; (l) if it is liquid; (g) if it is gas; (aq) if it is aqueous solution.

Example 1: Formation of liquid.

$2 H_{2(g)}+O_{2(g)} \rightarrow 2 H_{2} O_{(l)}$

• The hydrogen gas and oxygen gas reacts to form water which is a liquid.

Example 2: Formation of solid.

$A g N O_{3(a q)}+K C l_{(a q)} \rightarrow A g C l_{(s)}+K N O_{3(a q)}$

• The combination of aqueous silver nitrate and aqueous potassium chloride forms silver chloride which is a precipitate with potassium nitrate in the solution.

Example 3: Formation of gas.

$2 H C l_{(g)}+F_{2(g)} \rightarrow 2 H F_{(g)}+C l_{2(g)}$

• The hydrochloride gas reacts with fluorine gas to forms chloride gas with hydrogen fluoride gas.

(b) Balanced chemical reaction:

$Z n_{(S)}+2 H C l_{(g)} \rightarrow Z n C l_{2(s)}+H_{2(g)}$

(c) Balanced chemical reaction:

$F e S O_{4(a q)}+2 N a O H_{(a q)} \rightarrow F e(O H)_{2(s)}+N a_{2} S O_{4(a q)}.$