CBSE Class X – Science Chemistry Exam (Full Syllabus)

Identify the reducing agent in the following reactions: 2H₂O + 2F₂ → 4HF + O₂

Mention whether it is physical or chemical changes : Heating of an iron rod to red hot

State the reactions are exothermic or endothermic in nature: Dissolution of ammonium chloride in water

When copper turning are added to silver nitrate solution, a blue coloured solution is formed after some time. It is because copper ?

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 Subsequent salts does not carry water of crystallisation?

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:

identical volumes of hydrochloric acid and sodium hydroxide solutions of same concentration are mixed and the pH of the resulting solution is checked with a pH paper. What would be the colour obtained?

How many water molecules are present in plaster of paris

Common name calcium sulphate hemihydrate

Which of the following affirmation about the modern periodic table are inappropriate?

1. The elements in the modern periodic table are arranged on the basis of their decreasing atomic numbers
2. The elements in the modern periodic table are arranged on the basis of their increasing atomic masses.
3. Isotopes are placed in adjoining group(s) in the periodic table.
4. The elements in the modern periodic table are arranged on the basis of their increasing atomic number

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

Which of the following gives the accurate increasing order of the atomic radii of O, F and N?

Which of the following is the outermost shell for elements of period 2

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

A molecule of ammonia (NH₃) has:

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

The organic compounds having functional group are known as:

Ethane is

UnSaturated hydrocarbons contains

The electronic configurations of three elements X, Y and Z are X — 2, 8; Y — 2, 8, 7 and Z — 2, 8, 2. Which of the following is correct?

Name a metal that have very low melting points.

Why should we not throw small pieces of sodium into a sink in the laboratory? Because of

Why do ionic compounds conduct electricity in molten state? Because

A Metal that exists in liquid state at room temperature