CBSE Class X – Science Chemistry Exam (Full Syllabus)

Identify the reducing agent in the following reactions: Fe₂O₃ + 3CO → 2Fe + 3CO₂

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.Write the chemical name of the black precipitate formed.

Mention whether it is a physical or chemical changes: -Evaporation of petrol

Mention whether it is physical or chemical changes: Sublimation of solid ammonium chloride

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:

If 10 mL of H₂SO₄ is mixed with 10 mL of Mg(OH)₂ of the same concentration, the resultant solution will give the following colour with universal indicator:

Common salt other than being used in kitchen can also be used as the raw material for  making:

1. Washing soda
2. Bleaching powder
3. Baking soda
4. Slaked lime

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

How many water molecules are present in plaster of paris

On strong heating, blue coloured copper sulphate crystals turns

Where would you establish the element with electronic confguration 2, ǫ in the modern periodic table?

Which of the subsequent is the outermost shell for elements of period 2?

Which of the following elements does not lose an electron with ease?

Arrange the following elements in sequence of their increasing non-metallic character Li, O, C, Be and F.

The atomic number of an element is 20, its valency is

Which of he following compounds of carbon does not consist of ions?

How many number of carbon atoms are joined in a spherical molecule of buckminsterfullerene?

The I.U.P.A.C name of CH₃CH₂CH=CH₂ is?

The ability of an atom to form bonds with other atoms of the same element.

Saturated hydrocarbons contains

Which of the subsequent oxide(s) of iron would be obtained on prolonged reaction of iron with steam?

Hydrogen gas is not evolved when a metal reacts with nitric acid because

Give the formula of the stable binary compounds that would be formed by the combination of following pair of elements: Li and O₂

Name a metal which is highly malleable

When a metal X is treated with cold water, it gives a basic salt Y with molecular formula XOH (molecular mass = 40) and liberates a gas Z which easily catches fre. Identify X, Y and Z.