CBSE Class X – Science Chemistry Exam (Full Syllabus)

What happens when sodium sulphate solution is added to barium chloride solution?

Solid calcium oxide reacts vigorously with water to form calcium hydroxide, accompanied by liberation of heat. This process is called slaking of lime. Calcium hydroxide dissolves in water to form a solution called lime water. Which among the following is (are) true about slaking of lime and the solution formed?

1. It is an endothermic reaction
2. It is an exothermic reaction.
3. The pH of the resulting solution will be more than seven.
4. The pH of the resulting solution will be less than seven

One of the following processess doesnot require a chemical reaction:

Which among the following is (are) double displacement reaction(s)?

1. Pb + CuCl₂ → PbCl₂ + Cu
2. Na₂SO₄ + BaCl₂ → BaSO₄ + 2NaCl
3. C + O₂ → CO₂
4. CH₄ + 2O₂ → CO₂ + 2H₂O

Which of the following are combination reactions?

1. KClO₃   →^(Heat)→ 2KCl + 3O₂
2. MgO + H₂O → Mg(OH)₂
3. 4Al + 3O₂ → 2Al2O₃
4. Zn + FeSO₄ →ZnSO₄ + Fe

Sodium carbonate is a basic salt because it is a salt of:

What will take place when the solution of an acid is blend with the solution of a base in a test tube?

1. The temperature of the solution increases
2. The temperature of the solution decreases
3. The temperature of the solution remains the same
4. Salt formation takes place

Name the acid along present in ant sting

How many water molecules are present in plaster of paris

On strong heating, blue coloured copper sulphate crystals turns

An element which is a crucial constituent of all organic compounds belongs to:

Which of the following are the characteristics of isotopes of an element?

1. Isotopes of an element have the same atomic masses.
2. Isotopes of an element have the same atomic number
3. Isotopes of an element show the same physical properties.
4. Isotopes of an element show the same chemical properties.

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

Modern Periodic Law States that

Three elements B, Si and Ge are: Metalloids (d)

The electronic configuration of an element is found to be 2, 4. How many bonds can one carbon atom form in a compound?

Ester is formed by the reaction between:

The compounds formed by the sharing of electron pairs between two atoms.

Rich conductors of electricity.

Chemical name of the compound CH₃—CH₂—CH₂—Br

Shwetha took three beakers A, B and C containing zinc sulphate, silver sulphate and iron (II) sulphate solutions respectively. Copper pieces were added to each beaker. The solution will Become visible blue in the case of:

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

Non-metal that can exist in diferent forms

Name one non-metal that exist in liquid state at room temperature.

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.