Science and Technology I · Textbook solutions

Chemical Reactions and Equations

Every solved example, exercise, and miscellaneous question — in the order the textbook teaches them. · 31 questions

Exercise

31 q

Choose the correct option from the bracket and explain the statement giving reason. (Oxidation, displacement, electrolysis, reduction, zinc, copper, double displacement, decomposition)
Ex Q1(a) $To prevent rusting, a layer of ........ metal is applied on iron sheets.$
Ex Q1(b) $The conversion of ferrous sulphate to ferric sulphate is ........ reaction.$
Ex Q1(c) $When electric current is passed through acidulated water ........ of water takes place.$
Ex Q1(d) $\text{ZnSO}_4$
Write answers to the following.
Ex Q2(a) $What is the reaction called when oxidation and reduction take place simultaneously? Explain with one example.$
Ex Q2(b) $How can the rate of the chemical reaction, namely, decomposition of hydrogen peroxide be increased?$
Ex Q2(c) $Explain the term reactant and product giving examples.$
Ex Q2(d) $Explain the types of reaction with reference to oxygen and hydrogen. Illustrate with examples.$
Ex Q2(e) $Explain the similarity and difference in two events, namely adding NaOH to water and adding CaO to water.$
Explain the following terms with examples.
Ex Q3(a) $Endothermic reaction$
Ex Q3(b) $Combination reaction$
Ex Q3(c) $Balanced equation$
Ex Q3(d) $Displacement reaction$
Give scientific reasons.
Ex Q4(a) $When the gas formed on heating limestone is passed through freshly prepared lime water, the lime water turns milky.$
Ex Q4(b) $It takes time for pieces of Shahabad tile to disappear in HCl, but its powder disappears rapidly.$
Ex Q4(c) $While preparing dilute sulphuric acid from concentrated sulphuric acid in the laboratory, the concentrated sulphuric acid is added slowly to water with constant stirring.$
Ex Q4(d) $It is recommended to use air tight container for storing oil for long time.$
Ex Q5 $Observe the following picture a write down the chemical reaction with explanation.$
Identify from the following reactions the reactants that undergo oxidation and reduction.
Ex Q6(a) $\text{Fe} + \text{S} \rightarrow \text{FeS}$
Ex Q6(b) $2\text{Ag}_2\text{O} \rightarrow 4\,\text{Ag} + \text{O}_2\uparrow$
Ex Q6(c) $2\text{Mg} + \text{O}_2 \rightarrow 2\text{MgO}$
Ex Q6(d) $\text{NiO} + \text{H}_2 \rightarrow \text{Ni} + \text{H}_2\text{O}$
Balance the following equation stepwise.
Ex Q7(a) $\text{H}_2\text{S}_2\text{O}_7(l) + \text{H}_2\text{O}(l) \rightarrow \text{H}_2\text{SO}_4(l)$
Ex Q7(b) $\text{SO}_2(g) + \text{H}_2\text{S}(aq) \rightarrow \text{S}(s) + \text{H}_2\text{O}(l)$
Ex Q7(c) $\text{Ag}(s) + \text{HCl}(aq) \rightarrow \text{AgCl}\downarrow + \text{H}_2\uparrow$
Ex Q7(d) $\text{NaOH}(aq) + \text{H}_2\text{SO}_4(aq) \rightarrow \text{Na}_2\text{SO}_4(aq) + \text{H}_2\text{O}(l)$
Identify the endothermic and exothermic reaction.
Ex Q8(a) $\text{HCl} + \text{NaOH} \rightarrow \text{NaCl} + \text{H}_2\text{O} + \text{heat}$
Ex Q8(b) $2\text{KClO}_3(s) \xrightarrow{\Delta} 2\text{KCl}(s) + 3\text{O}_2\uparrow$
Ex Q8(c) $\text{CaO} + \text{H}_2\text{O} \rightarrow \text{Ca(OH)}_2 + \text{heat}$
Ex Q8(d) $\text{CaCO}_3(s) \xrightarrow{\Delta} \text{CaO}(s) + \text{CO}_2\uparrow$

Ex Q9

\text{BaCl}_2(aq) + \text{ZnSO}_4(aq)

Reactants	Products	Type of chemical reaction
$\text{BaCl}_2(aq) + \text{ZnSO}_4(aq)$	$\text{H}_2\text{CO}_3(aq)$	Displacement
$2\text{AgCl}(s)$	$\text{FeSO}_4(aq) + \text{Cu}(s)$	Combination
$\text{CuSO}_4(aq) + \text{Fe}(s)$	$\text{BaSO}_4\downarrow + \text{ZnCl}_2(aq)$	Decomposition
$\text{H}_2\text{O}(l) + \text{CO}_2(g)$	$2\text{Ag}(s) + \text{Cl}_2(g)$	Double displacement