NCERT Class 10 Science — Chapter 1: Chemical Reactions & Equations

Which of the following terms refers to an unbalanced chemical equation that uses correct chemical formulae for reactants and products but does not satisfy the law of conservation of mass?

Which gas is released during the photodecomposition of silver chloride?

Which gas is commonly used to flush potato chip packets to prevent oxidation?

When iron nails are immersed in an aqueous copper sulphate solution, which of the following changes are observed? 1. The iron nail retains its original silvery appearance. 2. The blue colour of the solution fades. 3. Ferrous sulphate is formed in the solution. Select the correct answer using the code given below.

The decomposition of vegetable matter into compost is an example of which type of reaction?

Which scientific law forms the basis for balancing chemical equations?

Which process is primarily used for the industrial production of quick lime (calcium oxide)?

What is the chemical identity of the solid residue obtained upon strongly heating lead nitrate?

With reference to chemical reactions, consider the following observations: 1. Change in state 2. Change in colour 3. Evolution of a gas 4. Change in temperature Which of the above generally indicate the occurrence of a chemical reaction?

Which product is formed when quick lime reacts vigorously with water?

Which gas is evolved when dilute sulphuric acid reacts with zinc granules?

With reference to whitewashing of walls using slaked lime, consider the following statements: 1. A shiny finish appears immediately after applying the solution. 2. The layer is formed by the reaction of calcium hydroxide with carbon dioxide in the air. 3. Marble has the same chemical formula as the layer formed on the walls. Which of the statements given above are correct?

The decomposition of silver chloride in sunlight is an example of which type of reaction?

What is the chemical composition of the white powder formed when magnesium ribbon burns in air?

In the reduction of copper(II) oxide by hydrogen, which of the following species is oxidised during the reaction?

Which of the following pairs of chemical compounds is primarily used in black and white photography due to their light-sensitive nature?

What is the common term for reactions involving simultaneous oxidation and reduction?

Assertion (A): Magnesium is oxidised when it burns in air to form magnesium oxide. Reason (R): The magnesium oxide formed turns moist blue litmus paper red.

What is the solid product formed when slaked lime reacts with carbon dioxide?

When aqueous solutions of sodium sulphate and barium chloride are mixed, a white precipitate is formed. What is the chemical identity of this precipitate?

Upon strong heating, copper powder forms a black solid. This chemical change is best described as:

Assertion (A): Skeletal chemical equations must be balanced before making quantitative calculations. Reason (R): Chemical equations provide information about the physical states of reactants and products.

Which of the following processes are exothermic in nature? 1. Reaction of quick lime with water 2. Decomposition of vegetable matter into compost 3. Thermal decomposition of calcium carbonate 4. Decomposition of silver chloride by sunlight Select the correct answer using the code given below.

What is the primary chemical reason that white silver chloride turns grey when exposed to sunlight?

Which of the following reactions is an example of a thermal decomposition process used in the industrial manufacture of cement?

Assertion (A): Respiration is considered an exothermic reaction. Reason (R): During respiration, glucose combines with oxygen in the cells to produce carbon dioxide and water along with energy.

Which of the following terms describes a chemical reaction that absorbs energy from its surroundings?

What is the primary objective of flushing packets of potato chips with nitrogen gas?

Assertion (A): The combustion of natural gas is an endothermic process. Reason (R): Methane reacts with oxygen to release a large amount of heat along with carbon dioxide and water.

The gradual formation of a green coating on copper and a black coating on silver upon exposure to air are examples of which process?

Consider the following statements regarding respiration as a chemical process: 1. It is an endothermic reaction. 2. It involves the breakdown of glucose with oxygen to release energy. 3. It releases oxygen as the primary byproduct. Which of the statements given above is/are correct?

What is the primary product formed when magnesium burns in the presence of oxygen?

During the electrolysis of water, which gas is collected in a volume double that of the other gas?

The brown fumes evolved upon heating lead nitrate are primarily composed of:

What is the characteristic colour of the corroded coating formed on silver?

What is the characteristic colour of the corroded coating formed on copper?

Which chemical compound is primarily present in the solution used for whitewashing walls?

Which of the following statements correctly describe oxidation and reduction reactions? 1. Oxidation is defined exclusively as the removal of oxygen. 2. Reduction involves the removal of oxygen from a substance. 3. Reduction may involve the addition of hydrogen. 4. Oxidation involves the gain of electrons. Select the correct answer using the code given below.