Class 10 Chemical Reactions and Equations Mock Test (CBSE)

Topics in Chemical Reactions and Equations

• Writing a chemical equation
• Balanced chemical equations
• Combination reaction
• Decomposition reaction
• Displacement reaction
• Double displacement reaction
• Oxidation and reduction
• Corrosion
• Rancidity

Chemical Reactions and Equations practice questions with answers

1. Q1Multiple choice·1 mark
   When ammonia ($\text{NH}_3$) reacts with oxygen ($\text{O}_2$) in the presence of a platinum catalyst, it produces nitric oxide ($\text{NO}$) and water vapour ($\text{H}_2\text{O}$). When the equation is balanced with the smallest whole-number stoichiometric coefficients, what is the sum of the coefficients of the gaseous products?

   1. (a)8
   2. (b)10
   3. (c)12
   4. (d)14
   Show answer and step marks

   1. Correct option: (b) 10. The balanced chemical equation is $4\text{NH}_3(g) + 5\text{O}_2(g) \rightarrow 4\text{NO}(g) + 6\text{H}_2\text{O}(g)$. The sum of the stoichiometric coefficients of the gaseous products ($\text{NO}$ and $\text{H}_2\text{O}$) is $4 + 6 = 10$.+1

   Answer: (b)
2. Q2Multiple choice·1 mark
   When solid lead(II) nitrate is heated strongly, it decomposes to form solid lead(II) monoxide, nitrogen dioxide gas, and oxygen gas. When the chemical equation is balanced using the smallest possible whole-number stoichiometric coefficients, what is the coefficient of nitrogen dioxide?

   1. (a)1
   2. (b)2
   3. (c)4
   4. (d)6
   Show answer and step marks

   1. Correct option: (c) 4+1

   Answer: (c)
3. Q3Multiple choice·1 mark
   When an iron nail is dipped in an aqueous copper sulphate solution, the blue colour of the solution gradually fades and turns into:

   1. (a)light green
   2. (b)yellow
   3. (c)colourless
   4. (d)deep blue
   Show answer and step marks

   1. Correct option: (a)+1

   Answer: (a)
4. Q4Assertion and reason·1 mark
   Assertion (A): In the reaction $\text{ZnO} + \text{C} \rightarrow \text{Zn} + \text{CO}$, carbon is getting oxidized to carbon monoxide. Reason (R): Oxidation is defined as the addition of oxygen or removal of hydrogen, while reduction is the addition of hydrogen or removal of oxygen.

   1. (a)Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
   2. (b)Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A).
   3. (c)Assertion (A) is true but Reason (R) is false.
   4. (d)Assertion (A) is false but Reason (R) is true.
   Show answer and step marks

   1. Correct option: (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).+1

   Answer: (a)
5. Q5Assertion and reason·1 mark
   Assertion (A): A chemical equation must be balanced to satisfy the law of conservation of mass. Reason (R): The total mass of reactants and products participating in a chemical reaction remains unchanged during the reaction.

   1. (a)Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
   2. (b)Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A).
   3. (c)Assertion (A) is true but Reason (R) is false.
   4. (d)Assertion (A) is false but Reason (R) is true.
   Show answer and step marks

   1. Correct option: (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).+1

   Answer: (a)
6. Q6Assertion and reason·1 mark
   Assertion (A): White silver chloride turns grey when kept in sunlight. Reason (R): Sunlight causes the decomposition of silver chloride into silver metal and chlorine gas.

   1. (a)Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
   2. (b)Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A).
   3. (c)Assertion (A) is true but Reason (R) is false.
   4. (d)Assertion (A) is false but Reason (R) is true.
   Show answer and step marks

   1. Correct option: (a)+1

   Answer: (a)

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