1. A pH below 7 indicates _______.   alkalinity   acidity   presence of ions   purity of the sample   Hint Half-n-half Clue   2. The lead of a pencil mainly contains _______.   graphite   carbon black   lead   plastics   Half-n-half Clue   3. Fill in the missing word: Acid + _______ = Salt + Water   Metal   Non Metal   Oxygen   Base   Half-n-half Clue   4. The 'fizz' in soft drinks is caused by _______.   nitrogen   Carbon dioxide   hydrogen   helium   Half-n-half Clue   5. Which of the following is not an acid?   NaOH   H2SO4   HNO3   HCl   Half-n-half Clue   6. What is the combination of any substance with oxygen known as?   Oxidation   Hydrogenation   Reduction   Combustion   Half-n-half Clue   7. A substance that speeds up the rate of a chemical reaction without undergoing any change itself is known as a _______.   cation   catalyst   counter ion   nucleus   Half-n-half Clue