1. What gas is evolved when HCl is poured on marble chips?   Hydrogen   Carbon Dioxide   Hydrogen Peroxide   Calcium Carbonate   Hint Half-n-half Clue   2. A space that contains no air or any gas is known as   Hollow   Pressurized Cabin   Vacuum   Bubble   Half-n-half Clue   3. Air is a   Gas   Plasma   Liquid   Solid   Half-n-half Clue   4. Lime water turns milky after carbon dioxide is passed through it.   True   False   5. Dry ice is   Very Cold Ice   Any Frozen Liquid   Ice with salt added   Solid Carbon Dioxide   Half-n-half Clue   6. When hydrogen peroxide acts on Manganese Dioxide, oxygen is produced.   True   False   7. Air is   An Element   An Alloy   A Compound   A Mixture   Half-n-half Clue