CBSE Class X – Science Chemistry Exam (Full Syllabus)

When hydrogen sulphide gas is passed through a blue solution of copper sulphate, the colour of the solution fades and a black precipitate is obtained.Name the type of reaction taking place.

Which of the subsequent is (are) an endothermic process(es)?

1. Dilution of sulphuric acid
2. Sublimation of dry ice
3. Condensation of water vapours
4. Evaporation of water

Which of the following reactions is an endothermic reaction?

When hydrogen sulphide gas is passed through a blue solution of copper sulphate a black precipitate of copper sulphide is obtained and the sulphuric acid so formed remain in the solution. The reaction is an example of a:

Three beakers labelled as A, B and C, each containing 25 ml of water, were taken. A small amount of NaOH, anhydrous CuSO4 and NaCl were added to the beakers A, B and C respectively. It was observed that there was an increase in the temperature of the solutions contained in beakers A and B, whereas in the case of beaker C, the temperature of the solution fell. Which one of the following statement(s) is (are) correct?

1. In beakers A and B, exothermic process has occurred.
2. In beakers A and B, endothermic process has occurred
3. In beaker C, exothermic process has occurred
4. In beaker C, endothermic process has occurred.

The chemical formula for plaster of Paris is :

To preserve tooth decay we are advised to brush our teeth regularly. The nature of the toothpaste commonly used is:

Which of the following substances will not give carbon dioxide on treatment with dilute acid?

An old person complained of acute pain in stomach. Doctor gave small antacid tablet and he got immediate relief. What actually happened?

What types of ions are formed when an acid is dissolved in water ?

The electronic confgurations of three elements X, Y and Z are: X : 2 Y : 2, 8, 7 Z : 2, 8, 2 Which of the following is true regarding these elements?

Which of the subsequent set of elements is written in sequence of their increasing metallic character?

Arrange these elements in decreasing order of their atomic radii

Arrange the following elements in increasing order of their atomic radii:

The atomic number of an element is 20, its electronic configuration.

A molecule of ammonia (NH₃) has:

Which of the followings is the major constituent of the liquefied petroleum gas?

Which of the following is the molecular formula of cyclobutane?

Unsaturated hydrocarbon undergoes incomplete combustion and burns with

Ethene is

Which among the following Declaration is incorrect for magnesium metal?

The metals that float when dealt with water are:

The poorest conductor of heat among metals is

Give the formula of the stable binary compounds that would be formed by the combination of following pair of elements: Al and Cl₂

A non-metal X exists in two diferent forms Y and Z. Y is the hardest natural substance, whereas Z is a good conductor of electricity. Identify X, Y and Z.