1. What gas is evolved when dilute sulfuric acid is added to zinc?   Argon   Hydrogen   Sulfur Dioxide   Hydrogen Peroxide   Hint Half-n-half Clue   2. Which of the following is not a physical change?   Decantation   Distillation   Precipitation   Oxidation   Half-n-half Clue   3. Which of the following is not an acid?   NaOH   HNO3   H2SO4   HCl   Half-n-half Clue   4. Which of the following is not an allotrope of carbon?   Diamond   Charcoal   Silk   Graphite   Half-n-half Clue   5. Catalysts speed up the rate of chemical reactions.   True   False   6. A substance that absorbs moisture is called _______.   hydrophobic   amorphous   hygroscopic   hydrophilic   Half-n-half Clue   7. Solubility of a substance in a solvent usually increases with an increase in temperature.   True   False