chemical reactions and equations objective type questions and answers
Questions
Free download in PDF Chemical Reactions and Equations Objective Type Questions and Answers for competitive exams. These short objective type questions with answers are very important for Board exams as well as competitive exams. These short solved questions or quizzes are provided by Gkseries.
21
Which among the following statement(s) is /are true? Exposure of silver chloride to sunlight for a long duration turns grey due to-
(i) The formation of silver by decomposition of silver chloride.
(ii) Sublimation of silver chloride.
(iii) Decomposition of chlorine gas from silver chloride.
(iv) Oxidation of silver chloride.
22
A dilute ferrous sulphate solution was gradually added to the beaker containing acidified permanganate solution. The light purple colour of the solution fades and finally disappears. Which of the following is the correct explanation for the observation?
A
KMnO4 is an oxidizing agent, it oxidizes FeSO4
B
FeSO4 acts as an oxidizing agent and oxidizes KMnO4
C
The colour disappears due to dilution, no reaction is involved
D
KMnO4 is an unstable compound and decomposes in the presence of FeSO4 to a colourless compound
23
In beakers A and B, exothermic process has occurred.
2. In beakers A and B, endothermic process has occurred.
3. In beaker C, exothermic process has occurred.
4. In beaker C, endothermic process has occurred.
24
Which of the following are exothermic processes?
I. Reaction of water with quick lime
II. Dilution of an acid
III. Evaporation of water
IV. Sublimation of camphor (crystals)
25
Three beakers labelled as A, B and C each containing 25 mL of water were taken. A small amount of NaOH, anhydrous CuSO4 and NaCl were added to the beakers A, B and C respectively. It was observed that there was an increase in the temperature of the solutions contained in beakers A and B, whereas in case of beaker C, the temperature of the solution falls. Which one of the following statement(s) is (are) correct?
I. In beakers A and B, exothermic process has occurred.
II. In beakers A and B, endothermic process has occurred.
III. In beaker C exothermic process has occurred.
IV. In beaker C endothermic process has occurred.
26
A dilute ferrous sulphate solution was gradually added to the beaker containing acidified permanganate solution. The light purple colour of the solution fades and finally disappears. Which of the following is the correct explanation for the observation?
A
KMnO4 is an oxidising agent, it oxidises FeSO4
B
FeSO4 acts as an oxidising agent and oxidises KMnO4
C
The colour disappears due to dilution; no reaction is involved
D
KMnO4 is an unstable compound and decomposes in presence of FeSO4 to a colourless compound
Answer: KMnO4 is an unstable compound and decomposes in presence of FeSO4 to a colourless compound
27
Which among the following is (are) double displacement reaction(s)?
I. Pb + CuCl2 ⇨ PbCl2 + Cu
II. Na2SO4 + NaCl2 ⇨ BaSO4 + 2NaCl
III. C + O2 ⇨ CO2
IV. CH4 + 2O2 ⇨ CO2 + 2H2O
28
Which among the following statement(s) is (are) true? Exposure of silver chloride to sunlight for a long duration turns grey due to
I. The formation of silver by decomposition of silver chloride
II. Sublimation of silver chloride
III. Decomposition of chlorine gas from silver chloride
IV. Oxidation of silver chloride
Answer: Heating copper wire in presence of air at high temperature
30
Solid calcium oxide reacts vigorously with water to form calcium hydroxide accompanied by liberation of heat. This process is called slaking of lime. Calcium hydroxide dissolves in water to form its solution called lime water. Which among the following is (are) true about slaking of lime and the solution formed?
I. It is an endothermic reaction
II. It is an exothermic reaction
III. The pH of the resulting solution will be more than seven
IV. The pH of the resulting solution will be less than seven
Answer: Combustion of Liquefied Petroleum Gas (LPG)
32
The following reaction is an example of a
4NH3 (g) + 5O2 (g) → 4NO (g) + 6 H2O (g)
1. Displacement reaction
2. Combination reaction
3. Redox reaction
4. Neutralisation reaction
33
Which of the following statements about the given reaction are correct?
3Fe(s) + 4H2O(g) → Fe3O4 (s) + 4H2 (g)
1. Iron metal is getting oxidized.
2. Water is getting reduced.
3. Water is acting as reducing agent.
4. Water is acting as oxidizing agent.
34
Which of the following are exothermic processes?
1. Reaction of water with quick lime
2. Dilution of an acid
3. Evaporation of water
4. Sublimation of camphor (crystals)
