1. What gas is evolved when dilute sulfuric acid is added to zinc?   Hydrogen   Argon   Hydrogen Peroxide   Sulfur Dioxide   Hint Half-n-half Clue   2. Which of the following is not an allotrope of carbon?   Silk   Charcoal   Diamond   Graphite   Half-n-half Clue   3. Solubility of a substance in a solvent usually increases with an increase in temperature.   True   False   4. Acids turn blue litmus paper _______.   yellow   colorless   pink   red   Half-n-half Clue   5. Which of the following is a chemical change?   Dissolving of salt in water   Freezing of water   Boiling of water   Rusting of iron   Half-n-half Clue   6. The 'fizz' in soft drinks is caused by _______.   nitrogen   hydrogen   helium   Carbon dioxide   Half-n-half Clue   7. Which of the following is not an acid?   HCl   HNO3   H2SO4   NaOH   Half-n-half Clue