Decomposition Reaction

Q.

Explain the following types of chemical reactions giving two examples for the each of them :

(a) combination reaction

(b) decomposition reaction

(c) displacement reaction

(d) double displacement reaction

Q. Balance the following chemical equations:

$1.{\mathrm{Fe}}_2{\left({\mathrm{SO}}_4\right)}_3+\mathrm{KOH}\to K_2{\mathrm{SO}}_4+\mathrm{Fe}{\left(\mathrm{OH}\right)}_{3}2.{\mathrm{Ca}}_3{\left({\mathrm{PO}}_4\right)}_2+{\mathrm{SiO}}_2\to P_4{O}_{10}+{\mathrm{CaSiO}}_{3}3.{\mathrm{KClO}}_3\to {\mathrm{KClO}}_4+\mathrm{KCl}4.C_7{H}_6{O}_2+O_2\to {\mathrm{CO}}_2+H_{2}O$

Q.

Silver chloride turns grey because of the formation of which the following when placed in the sun?

1. Carbon dioxide
2. Silver oxide
3. Silver sulphate
4. Silver metal

Q.

When crystals of lead nitrate are heated s in a dry test tube

1. crystals immediately melt

2. a brown residue is left

3. white fumes appear in the tube

4. a yellow residue is left

Q. Is the equation is correct:2KCLO3 /2KCL+3O2

Q.

What are the ten examples of electrolytic decomposition reaction?

Q.

___________ gas is evolved on heating lead nitrate and ____________ gas is evolved on heating sodium nitrate.

Q.

A decomposition reaction is generally exothermic.

1. True
2. False

Q.

The reaction in which a single reactant breaks down to give simpler products is called __ reaction.

Q.

Name the following:

A reaction in which a substance breaks up into two or more simpler substances.

Q.

What type of reaction is
$2KCl{O}_3\left(s\right)\stackrel{Heat}{\to }2KCl\left(s\right)+3O_2\left(g\right)?$

1. Combination reaction

2. Thermal decomposition reaction

3. Photo decomposition reaction

4. Displacement reaction

Q.

Identify the type of reaction and product(s) formed when hydrogen peroxide$H_2{O}_2$is heated.

1. Products:- Water, Carbondioxide gas

   Type of reaction:- Thermal decomposition

2. Products:- Water , Oxygen gas

   Type of reaction:- Electrolytic decomposition

3. Products:- water, oxygen gas

   Type of reaction:- Combination reaction

4. Products:-Water, Oxygen gas

   Type of reaction:- Thermal decomposition

Q. The following reaction is an example of a
$2Pb\left(N{O}_3{)}_2\right(s\left)\stackrel{Heat}{\to }2PbO\right(s)+4N{O}_2(g)+O_2(g)$
I. Combination reaction
II. Decomposition reaction
III. Endothermic reaction
IV. Exothermic reaction

1. I & III
2. II & III
3. II & IV
4. I & IV

Q.

Identify the following reaction.

${\mathrm{ZnCO}}_3\to \mathrm{ZnO}+{\mathrm{CO}}_2$

Q. Balance the following chemical equations:

$1.{\mathrm{Fe}}_2{\left({\mathrm{SO}}_4\right)}_3+\mathrm{KOH}\to K_2{\mathrm{SO}}_4+\mathrm{Fe}{\left(\mathrm{OH}\right)}_{3}2.{\mathrm{Ca}}_3{\left({\mathrm{PO}}_4\right)}_2+{\mathrm{SiO}}_2\to P_4{O}_{10}+{\mathrm{CaSiO}}_{3}3.{\mathrm{KClO}}_3\to {\mathrm{KClO}}_4+\mathrm{KCl}4.C_7{H}_6{O}_2+O_2\to {\mathrm{CO}}_2+H_{2}O$

Q. In the balanced equation:
${\mathrm{aFe}}_2{O}_3+{\mathrm{bH}}_2\to \mathrm{cFe}+{\mathrm{dH}}_{2}O$
The value of a, b, c, d are respectively ________

1. 1, 3, 2, 3
2. 1, 1, 1, 1
3. 1, 1, 2, 3
4. 1, 2, 2, 3

Q.

The decomposition reaction in which heating is involved is called thermal decomposition.

1. True

2. False

Q. $2{\text{Pb(NO}}_3{)}_2\text{(s)}\stackrel{\text{Heat}}{\to }2\text{PbO(s)}+4{\text{NO}}_2\text{(g)}+{\text{O}}_2\text{(g)}$

The reaction given above is an example of a/an:

1. decomposition reaction
2. exothermic reaction
3. endothermic reaction
4. combination reaction

Q.

When silver chloride is exposed to light, it decomposes to form silver metal and chlorine gas.

1. True
2. False

Q.

Name the gas that evolved at cathode and anode when water is electrolysed. State their ratio by volume.

Q. Match the following reactions with their respective types of reactions .

1. Combination
2. Decomposition
3. Displacement

Q.

Which of the following is a decomposition reaction?

1. CH₄ + 2O₂ →CO₂ + 2H₂O

2. 2Pb(NO₃)₂ → 2PbO + 4NO₂+ O₂

3. 3Fe + 4H₂O → Fe₃O₄ + 4H₂

4. 2 KI +Cl₂ → 2KCl +I₂

Q. Oxygen gas is evolved during the decomposition of $H_2{O}_2$

1. False
2. True

Q. A metal nitrate gives ${\text{NO}}_2\text{and}{\text{O}}_2$ on simple heating. This metal nitrate is:

1. ${\text{NaNO}}_3$
2. ${\text{AgNO}}_3$
3. ${\text{Cu(NO}}_3{)}_2$
4. ${\text{P(NO}}_3{)}_2$

Q. Identify the type of the reaction given below:

$2{\text{KClO}}_3\text{(s)}\stackrel{\text{Heat}}{\to }2\text{KCl(s)}+3{\text{O}}_2\text{(g)}$

1. Combination reaction
2. Thermal decomposition reaction
3. Photo decomposition reaction
4. Displacement reaction

Q. Which among the following is(are) double displacement reaction(s)?
(i) $Pb+CuC{l}_2\to PbC{l}_2+Cu$
(ii) $N{a}_{2}S{O}_4+BaC{l}_2\to BaS{O}_4+2NaCl$
(iii) $C+O_2\to C{O}_2$
(iv) $C{H}_4+2O_2\to C{O}_2+2H_{2}O$

1. (i) and (iv)
2. (ii) only
3. (i) and (ii)
4. (iii) and (iv)

Q. Give one example of each which illustrates the following characteristics of a chemical reaction: ​

(c) Change in state

Q. Identify the type of chemical reaction taking place when silver chloride turns black on exposure to sunlight.

1. Decomposition reaction
2. Displacement reaction
3. Combination reaction
4. Double displacement reaction

Q.

The process in which a compound is decomposed to its constituents is called chemical ___.

Q.

Conversion of $CaC{O}_3$ into $CaO$ as per the following reaction is an example of:

$CaC{O}_3\left(s\right)\stackrel{heat}{\to }Cao\left(s\right)+C{O}_2\left(g\right)$

1. Decomposition reaction.

2. Reduction reaction.

3. Oxidation reaction.

4. Displacement reaction