NTSE MCQs 1 on "ATOMS AND MOLECULES"

These are MCQs 1 of "ATOMS AND MOLECULES" . Practice MCQs to check your knowledge for Entrance examination like NTSE etc.

1. If isotopic distribution of C-12 & C-14 is 98% and 2% respectively, then number of C-14 atoms in 12 g of C is:

• 1.244 X 10²²
• 1.244 X 10²³
• 3.88 X 10²²
• 3.88 X 10²²

2. Identify the correct symbol of gold:

• Go
• Ge
• Gd
• Au

3. The combining capacity of an element is called

• Valency
• Atomicity
• Atomic number
• Valence electrons

4. Which is not represented by 1 mole of Nitrogen gas?

• 6.023 X 10²³ molecules of N₂
• 12.046 X 10²³ atoms of N₂
• 6.023 X 10 ²³ atoms of N₂
• 28g of N₂

5. 18g of water is electrolysed. The weight of oxygen obtained is:

• 16g
• 8g
• 4g
• 1g

6. The balancing of chemical equations is in accordance with:

• Law of combining volumes
• Law of constant proportions
• Law of conservation of mass
• Both b and c

7. Which of the following is a correct statement:

• Na₂S is sodium sulphide, Na₂SO₃ is sodium sulphite, Na₂SO₄ is sodium sulphate
• Na₂S is sodium sulphite, Na₂SO₃ is sodium sulphide, Na_{2SO4 is sodium sulphate}
• Na₂S is sodium sulphide, Na₂SO₃ is sodium sulphate, Na₂SO₄ is sodium sulphite
• Na₂S is sodium sulphite, Na₂SO₃ is sodium sulphite, Na₂SO₄ is sodium sulphide

8. The formula of Calcium phosphate is:

• CaPO₄
• Ca(PO₄)₂
• Ca₃(PO₄)₂
• Ca₂(PO₄)₃

9. Molecular weight of CuSO4.5H2O is equal to:

• 249.5
• 159.5
• 159.5 X 90
• 159.5 + 10 + 16

10. How many moles of electrons weigh 1 kg. Mass of an electron is 9.1X10-31

• 6.022 X 10²³
• 6.022 X 10²³/9.1X10^-31
• 1 X 10³¹/9.1
• 10⁸/9.1 X 6.022