1. Which of the following is not a physical change?   Oxidation   Distillation   Precipitation   Decantation   Hint Half-n-half Clue   2. What is the combination of any substance with oxygen known as?   Hydrogenation   Oxidation   Reduction   Combustion   Half-n-half Clue   3. Catalysts often speed up certain chemical reactions.   False   True   4. If no more solute can be dissolved in a solvent at a given temperature then that solution is called   An Unstable Solution   A Real Solution   A Saturated Solution   A Dispersed Solution   Half-n-half Clue   5. Fill in the missing word Acid + _______ = Salt + Water   Oxygen   Metal   Non Metal   Base   Half-n-half Clue   6. A substance which speeds up a chemical reaction without itself getting affected is known as a   Counter Ion   Nucleus   Cation   Catalyst   Half-n-half Clue   7. Acids change a litmus paper from   Red to Blue   Blue to Red   Red to Purple   Green to White   Half-n-half Clue