English Medium Class 10 - CBSE Question Bank Solutions

Which one of the following processes involve chemical reactions?

In which of the following chemical equations, the abbreviations represent the correct states of the reactants and products involved at reaction temperature?

Which of the following are combination reactions?

1. `2"KClO"_3 overset("Heat")(->) 2"KCl" + 3"O"_2`
2. `"MgO" + "H"_2"O" -> "Mg"("OH")_2`
3. `4"Al" + 3"O"_2 -> 2"Al"_2"O"_3`
4. `"Zn" + "FeSO"_4 -> "ZnSO"_4 + "Fe"`

Write the balanced chemical equations for the following reactions and identify the type of reaction in each case.

1. Nitrogen gas is treated with hydrogen gas in the presence of a catalyst at 773 K to form ammonia gas.
2. Potassium hydroxide solution is treated with acetic acid to form potassium acetate and water.
3. Ethanol is warmed with ethanoic acid to form ethyl acetate in the presence of concentrated H₂SO₄.
4. Ethene is burnt in the presence of oxygen to form carbon dioxide, water and release heat and light. 

Write the balanced chemical equations for the following reactions and identify the type of reaction in each case.

1. Iron (III) oxide reacts with aluminum and gives molten iron and aluminum oxide.
2. Magnesium ribbon is burnt in an atmosphere of nitrogen gas to form solid magnesium nitride.
3. Chlorine gas is passed in an aqueous potassium iodide solution to form potassium chloride solution and solid iodine.
4. Ethanol is burnt in air to form carbon dioxide, water and releases heat. 

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

`"Pb"("NO"_3)_2("aq") + 2"Kl"("aq") -> "Pbl"_2(x) + 2"KNO"_3("y")`

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

`"Cu"("s") + 2"AgNO"_3("aq") -> "Cu"("NO"_3)_2("aq") + x("s")`

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.