Chapter 01 Chemical Reactions and Equations Questions-01
QUESTIONS
1. Why should a magnesium ribbon be cleaned before burning in air?
Show Answer
Answer
Magnesium is very reactive metal. When stored it reacts with oxygen to form a layer magnesium oxide on its surface. This layer of magnesium oxide is quite stable and prevents further reaction of magnesium with oxygen. The magnesium ribbon is cleaned by sand paper to remove this layer so that the underlying metal can be exposed into air.
2. Write the balanced equation for the following chemical reactions.
(i) Hydrogen + Chlorine → Hydrogen chloride
(ii) Barium chloride + Aluminium sulphate → Barium sulphate + Aluminium chloride
(iii) Sodium + Water → Sodium hydroxide + Hydrogen
Show Answer
Answer
(i) $H _{2(g)}+Cl _{2(g)} \longrightarrow 2 HCl _{(g)}$
(ii) $3 BaCl _{2(s)}+Al_2(SO_4) _{3(s)} \longrightarrow 3 BaSO _{4(s)}+2 AlCl _{3(s)}$
(iii) $2 Na _{(s)}+2 H_2 O _{(l)} \longrightarrow 2 NaOH _{(a q)}+H _{2(g)}$
3. Write a balanced chemical equation with state symbols for the following reactions.
(i) Solutions of barium chloride and sodium sulphate in water react to give insoluble barium sulphate and the solution of sodium chloride.
(ii) Sodium hydroxide solution (in water) reacts with hydrochloric acid solution (in water) to produce sodium chloride solution and water.
Show Answer
Answer
(i) $BaCl_2(a q)+ Na_2 SO_4(a q) \longrightarrow BaSO _4(s)+2 NaCl (a q)$
$ \begin{aligned} (ii) ~NaOH (a q)+HCl(a q) \rightarrow NaCl (a q)+H_2 O (j) \end{aligned} $
