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Science quiz

Chemical reaction

1.) In the balanced equation – a F e 2 O 3 + b H 2 → c F e + d H 2 O The value of a, b, c, d are respectively-

a)1,1,2,3

b) 1,2,2,3

c) 1,3,2,3

d) 1,1,1,1

2. Which of the following statements is correct?

5 question

a) All of these

b) A chemical equation tells us about 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) A chemical equation informs us about the symbols and formulae of the substances involved in a reaction.

3.) The respiration process during which glucose undergoes slow combustion by combining with oxygen in the cells of our body to produce energy, is a kind of:

a) C a O + C O 2 → C a C O 3

b)S O 2 + 1/ 2 O 2 → S O 3

c) 4 N a + O 2 → 2 N a 2 O

d) 2 N a + 2 H 2 O → 2 N a O H + H 2

4.). Which of the following statements is/are true

a) The total mass of the substance remains same in a chemical change.

b) A physical change is temporary and reversible.

c) All of these

d) A chemical change is permanent and irreversible.

5.) OnThe equation - C u + x H N O 3 → C u ( N o 3 ) 2 + y N O 2 + 2 H 2 O The value of x and y are –

a) 7 and 1

b) 3 and 5

c) 8 and 6

d) 4 and 2

6.) In the reaction F e S O 4 + x → N a 2 S O 4 + F e ( O H ) 2 , x is –

a) N a O H

b) none of these

c) H 2 S O 4

d) N a 2 S O 4

7.) Which of the following reactions is not balanced

a)2 N a H C O 3 → N a 2 C O 3 + H 2 O + C O 2

b) 4 N H 3 + 5 O 2 → 4 N O + 6 H 2 O

c) 2 C 4 H 10 + 120 2 → 8 C O 2 + 10 H 2 O

d) 2 A l + 6 H 2 O → 2 A l ( O H ) 3 + 3 H 2

8.) . Which of the following is/are a decomposition reaction(s)?

a) 2 H 2 O E l e c t r o l y s i s −−−−−−−→ H 2 + O 2

b) C a C O 3 H e a t −−−→ C a O + C O 2

c) All of these

d) 2 H g O H e a t −−−→ 2 H g + O 2

9.) Chemical reaction 2 N a + C 1 2 → 2 N a C I is an example of

a) displacement reaction

b) decomposition reaction

c) double displacement reaction

d)Combination reaction

10.) In the reaction x P b ( N O 3 ) 32 H e a t −−−→ y P b o + z N O 2 + O 2 , x , y and z are-

a) 4,2,2

b) 1,1,2

c) 2,2,4

d) 1,2,4

11.) When dilute hydrochloric acid is added to iron filling –

a) iron salt and water are produced.

b) no reaction takes place.

c) chlorine gas and ferric hydroxide are produces.

d) hydrogen gas and ferric chloride are produced.

12.) The displacement reaction between iron (III) oxide and a metal X is used for welding the rail tracks. Here X is:

a)Copper granules

b)Magnesium ribbon

c)Sodium pellets

d)Aluminium dust

13.) Which of the following equations is not an example of single displacement reaction?

a) 2 N a + 2 H 2 O → 2 N a O H + H 2

b) 2 A l + F e 2 O 3 → A I 2 O 3 + 23 F e

c) 2 K I + C I 2 → 2 K C I + I 2

d) C a + C O 2 → C a C O 2

14.) . Neutralization reaction is an example of –

a) none of these

b) oxidation

c) endothermic reaction

exothermic reaction

15.) Z n ( s ) + H 2 S O 4 ( a q ) → Z n S O 4 ( a q ) + H 2 ( g ) is an example of -

a) Reactio change in color

b) evolution of gascorrect