Class 10 Science Chapter 1 Chemical Reactions and Equations

Consider the reaction: S(s) + O₂(g) → SO₂. The state of SO₂ in this reaction is

Which of the following are exothermic processes?

• Reaction of water with quick lime

• Dilution of an acid

• Evaporation of water

• Sublimation of camphor (crystals)

Which of the following statements about the given reaction are correct? 3Fe (s) + 4H2O (g) → Fe3O4 (s) + 4 H2 (g)

• (i) Iron metal is getting oxidised

• (ii) Water is getting reduced

• (iii) Water is acting as reducing agent

• (iv) Water is acting as oxidising agent

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

• Displacement reaction

• Precipitation reaction

• Combination reaction

• Double displacement reaction

The color of magnesium oxide is

• White

• Blue

• Grey

• Pink

Chemically rust is

• hydrated ferrous oxide

• only ferric oxide

• hydrated ferric oxide

• none of these

When a magnesium ribbon is burnt in the air, the ash formed is

• Black

• White

• Yellow

• Pink

The reaction in which two compounds exchange their ions to form two new compounds is called

• Displacement reaction

• Combination reaction

• Double displacement reaction

• Redox reaction

When crystals of lead nitrate are heated strongly in a dry test tube

• Crystals immediately melt

• A brown residue is left

• White fumes appear in the tube

• A yellow residue is left

In which of the following, heat energy will be evolved?

• Electrolysis of water

• Dissolution of NH4Cl in water

• Burning of L.P.G.

• Decomposition of AgBr in the presence of sunlight