| 1 |
Many element have fractional atomic masses. This is because. |
- A. the mass of the atom is itself fractional
- B. Atomic masses are average mases of Isobars
- C. Atomic masses are average masses Isotopes
- D. Atomic masses are average masses of Isotopes proportional to their relative abundance.
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| 2 |
Which of the following compound has the highest % o f oxygen by weight |
- A. CH<sub>3</sub>- OH
- B. C<sub>2</sub>H<sub>5</sub>OH
- C. HCOOH
- D. H<sub>2</sub>O
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| 3 |
Isotopes differ in. |
- A. Properties which depend upon mass
- B. Arrangement of electrons in orbitals
- C. Chemical properties
- D. None of these
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| 4 |
Bromine has isotopes |
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| 5 |
The volume occupied by 1.6 g of O<sub>2</sub>at STP is |
- A. 22.4 dm<sup>3</sup>
- B. 2.24 dm<sup>3</sup>
- C. 1.12 dm<sup>3</sup>
- D. 112 dm<sup>3</sup>
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| 6 |
Actual yield is mostly less than the theoretical yield due to the reason that |
- A. Rates of reactions are slow
- B. Loss of the product during handling
- C. Reactions are never completed 100%
- D. Law of conservation of mass is not true
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| 7 |
the volume occupied by 1.4 of N2 at S.T.P is |
- A. 2.24 dm3
- B. 22.4 dm3
- C. 1.12 dm3
- D. 112 cm3
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| 8 |
In stoichiometric calculations |
- A. The reaction can be reversile
- B. Side products can be formed
- C. Law of conservation of mass may not be obeyed
- D. Law of definite proportions is definitely obeyed
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| 9 |
The Avogadro constant is the number of. |
- A. Atoms in 1 g of helium ga
- B. Molecules in 35.5 g of chlorine gas
- C. Atoms in 6 h graphite
- D. Atoms in 24 g of magnesium
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| 10 |
In mass spectrometry, ions are produced by |
- A. Heat at high temperature
- B. Passing gas through high voltage plates
- C. Throwing fast moving electrons on gas molecules
- D. All of them
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