English Medium Class 10 - CBSE Question Bank Solutions for Science

Complete the missing component /variable  given as x and y in the following reactions

`"Zn"("s") + "H"_2"SO"_4("aq") -> "ZnSO"_4(x) + "H"_2("y")`

Complete the missing component/variable given as x and y in the following reactions

`"CaCO"_2(s)overset(x)(->) "CaO"("s") + "CO"_2("g")`

Which among the following change is exothermic or endothermic in nature?

Decomposition of ferrous sulphate

Which among the following change is exothermic or endothermic in nature?

Dilution of sulphuric acid

Which among the following change is exothermic or endothermic in nature?

Dissolution of sodium hydroxide in water

Which among the following change is exothermic or endothermic in nature?

Dissolution of ammonium chloride in water

A solution of potassium chloride when mixed with silver nitrate solution, an insoluble substance is formed. Write the chemical reaction involved and mention the type of the chemical reaction.

Write the balanced chemical equation for the following reaction

Sodium carbonate on reaction with hydrochloric acid in equal molar concentrations gives sodium chloride and sodium hydrogencarbonate.

Write the balanced chemical equation for the following reaction

Sodium hydrogencarbonate on reaction with hydrochloric acid gives sodium chloride, water and liberates carbon dioxide.

Write the balanced chemical equation for the following reaction

Copper sulphate on treatment with potassium iodide precipitates cuprous iodide (Cu₂I₂), liberates iodine gas and also forms potassium sulphate.

Ferrous sulphate decomposes with the evolution of a gas having a characteristic smell of burning sulphur. Write the chemical reaction involved and identify the type of reaction.

Why do fire flies glow at night ?

A substance X, which is an oxide of a group 2 element, is used intensively in the cement industry. This element is present in bones also. On treatment with water it forms a solution which turns red litmus blue. Identify X and also write the chemical reactions involved.

Write a balanced chemical equation of the following reaction and also classify them.

Lead acetate solution is treated with dilute hydrochloric acid to form lead chloride and acetic acid solution.

Write a balanced chemical equation of the following reaction and also classify them.

A piece of sodium metal is added to absolute ethanol to form sodium ethoxide and hydrogen gas.

Write a balanced chemical equation of the following reaction and also classify them.

 Iron (III) oxide on heating with carbon monoxide gas reacts to form solid iron and liberates carbon dioxide gas.

Write a balanced chemical equation of the following reaction and also classify them.

Hydrogen sulphide gas reacts with oxygen gas to form solid sulphur and liquid water.

A magnesium ribbon is burnt in oxygen to give a white compound ‘X’ accompanied by emission of light. If the burning ribbon is now placed in an atmosphere of nitrogen, it continues to burn and forms a compound ‘Y’.

1. Write the chemical formulae of X and Y.
2. Write a balanced chemical equations when X and Y are dissolved in water.

What happens when a piece of

1. zinc metal is added to copper sulphate solution?
2. aluminium metal is added to dilute hydrochloric acid?
3.  silver metal is added to copper sulphate solution?

Also write the balanced chemical equation if the reaction occurs.

What happens when

1. ZnCO₃ is heated in the absence of oxygen?
2. a mixture of Cu₂O and Cu₂S is heated?