Question

Q3. The equation - Cu + xHNO3 → Cu(NO3)2 + yNO2 + 2H20
The values of x and y are-
(A) 3 and 5
(B) 8 and 6
(C) 4 and 2
(D) 7 and 1


Q4. Neutralization reaction is an example of:
(A) exothermic reaction
(B) endothermic reaction
(C) oxidation
(D) none of these


Q5. Which of the following statements is/are true :
(A) The total mass of the substance remains same in a chemical change.
(B) A chemical change is permanent and irreversible.
(C) A physical change is temporary and reversible.
(D) All of these.


Q6. Which of the following statements is correct :
(A) A chemical equation tells us about the substances involved in a reaction.
(B) A chemical equation informs us about the symbols and formulae of the substances
involved in a reaction.
(C) A chemical equation tells us about the atoms or molecules of the reactants and products involved in a reaction.
(D) All are correct.


Q7. Zn(s) + H2SO4(aq) — ZnSO4(aq) + H2(g) is an example of:
(A) precipitation reaction
(B) endothermic reaction
(D) change in colour
(C) evolution of gas

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Answer 1

Answer:

3-C

4-A

5-4

6-D

7-C

Explanation: