Class 10 Science PT 1 Exam 2023-24

Which of the statements about the reaction below are incorrect?

2PbO(s) + C(s) → 2Pb(s) + CO2(g)

i. Lead is getting reduced.

ii. Carbon dioxide is getting oxidized.

iii. Carbon is getting oxidized.

iv. Lead oxide is getting reduced.→

• (i) and (ii)

• (i) and (iii)

• (i), (ii) and (iii)

• (iv) only

Which of the following is not a balanced equation?

• H2+ O2→H2O

• Mg + CuSO2→MgSO4+ Cu

• NaOH + HCI→NaCI + H2O

• Zn + S ⟶ ZnS

Aluminum reacts with copper sulphate to produce

• Cu and Al2(SO4)3

• CuO and Al2(SO4)3

• Cu, Al2S3Al2S3 and SO2

• CuO, Al2S3Al2S3 and SO2

What happens when dilute HCl is added to iron filings? Tick the correct answer.

• Chlorine gas and iron hydroxide are produced.

• Iron salt and water are produced.

• Hydrogen gas and iron chloride are produced.

• No reaction takes place.

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

• (i) and (ii)

• (ii) and (iii)

• (i) and (iv)

• (iii) and (iv)

Which among the following are endothermic processes?

i. Reaction of quick lime with water

ii. Dilution acid with water

iii. Evaporation of water

iv. Sublimation of solid ammonium chloride

• (i) and (ii)

• (ii) and (iii)

• (i) and (iv)

• (iii) and (iv)

Barium chloride on reacting with ammonium sulphate forms barium sulphate and ammonium chloride. Which of the following correctly represents the type of the reaction involve?

i. Displacement reaction

ii. Precipitation reaction

iii. Combination reaction

iv. Double displacement reaction

• (i), (iii)

• (ii), (iii)

• (iii)

• (ii), (iv)

The electrolytic decomposition of water gives H2and O2 in the ratio of

• 1:2 by volume

• 2:1 by volume

• 1:2 by mass

• 8:1 by mass

Which of the following is not a physical change?

• Boiling of water to give water vapour

• Melting of ice to give water

• Dissolution of salt in water

• Combustion of Liquefied Petroleum Gas (LPG)

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)

• 1 and 2

• 2 and 3

• 1 and 4

• 3 and 4