Chemical Reactions Quiz

Which of the following is the correct observation of the reaction shown in the following setup?

• Brown powder of Magnesium oxide is formed.

• Colourless gas which turns lime water milky is evolved.

• Magnesium ribbon burns with brilliant white light.

• Reddish brown gas with a smell of burning Sulphur has evolved.

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

• (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

Which of the following are exothermic processes?

• (i) Reaction of water with quick lime

• (ii) Dilution of an acid

• (iii) Evaporation of water

• (iv) Sublimation of camphor (crystals)

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?

• It is an endothermic reaction.

• It is an exothermic reaction.

• The pH of the resulting solution will be more than seven.

• The pH of the resulting solution will be less than seven.

Which among the following statement(s) is (are) true? Exposure of silver chloride to sunlight for a long duration turns grey due to

• the formation of silver by decomposition of silver chloride

• sublimation of silver chloride

• decomposition of chlorine gas from silver chloride

• oxidation of silver chloride

MnO2 + 4HCl → MnCl2 + 2H2O + Cl2 Identify the substance reduced in the above equation.

• MnCl2

• HCl

• 2H2O

• MnO2

Ethane (C2H6) on complete combustion gave CO2 and water. It shows that the results are in accordance with the law of conservation of mass. Then, the coefficient of oxygen is equal to

• 7/2

• 3/2

• 5/2

• 9/2

The science teacher said to Sahil to perform an experiment with lead nitrate and potassium iodide. He done the following steps under the observation of teacher. 1. Take lead nitrate solution in a beaker. 2. Take potassium iodide solution in a test tube. (Both solutions are colourless). 3. Add potassium iodide solution slowly to the lead nitrate solution. Which chemical reaction take place here?

• Pb(NO3) + 2KI ..... PbI2 + 2KNO3

• Pb(NO3) + KI ...... PbI2 + 2NO3

• Pb(NO3) + I ...... PbI + 2K

• Pb(NO3) + 2KI ..... 2 PbI2 + 2KNO3

Four students A B C and D were asked to carry out a decomposition reaction. Each one followed different method as mentioned – 1) Heated aqueous solution of iron sulphate in a test tube 2) Added Zn granules to iron sulphate in a test tube and then heated the mixture 3) Heated crystals of iron sulphate in a test tube 4) Heated crystals of iron sulphate along with copper sulphate crystals in a china dish The student who adopted the correct method is

• 1

• 2

• 3

• 4

Identify gas A in the following experiment.

• Nitrogen

• Hydrogen

• Oxygen

• Carbon dioxide