1. Q: What is the acid produced in the stomach?
Q: What are the two functions of the acid produced in the stomach?
Q: How do indigestion remedies (antacids) work?
Q: How could you investigate the effectiveness of different indigestion remedies?
Q: State the three classes of compound that can neutralise acids.
Q: What are the general products when an acid reacts with a metal oxide?
Q: What are the general products when an acid reacts with a metal hydroxide?
Q: What are the general products when an acid reacts with a metal carbonate?

2. A: They contain substances that neutralise excess stomach acid.
A: It helps with digestion; it helps to destroy bacteria that are accidently consumed.
A: Hydrochloric acid.
A: Use a specific amount of acid with a known pH, then add an antacid tablet and allow it to react, then check the pH. Repeat this with different tablets. The tablet that raised the pH the most would be the most effective.
A: They contain substances that neutralise excess stomach acid.
A: Salt and water.
A: Metal oxides, metal hydroxides and metal carbonates.
A: Salt, water and carbon dioxide.

3. Q: What type of salts are produced by hydrochloric acid?
Q: What type of salts are produced by sulfuric acid?
Q: What type of salts are produced by nitric acid?
Q: What is electrolysis?
Q: What are the products of decomposition of hydrochloric acid by electrolysis?
Q: What is the chemical test for hydrogen?
Q: What is the chemical test for chlorine?
Q: How do we obtain chlorine gas?

4. A: By the electrolysis of seawater (a solution of sodium chloride).
A: Sulfates.
A: Chlorides.
A: A process in which electrical energy, from a d.c. supply, decomposes compounds.
A: Nitrates.
A: A glowing splint will cause a small explosion characterised by a popping sound in hydrogen.
A: Hydrogen and chlorine (gases).
A: By the electrolysis of seawater (a solution of sodium chloride).
A: Has a very distinctive strong smell; will extinguish a glowing splint; will turn moist litmus paper or UI paper red then bleach it white.

5. Q: What are the hazards of chlorine gas?
Q: What special precautions need to be taken in the large-scale industrial productions of chlorine?
Q: State three uses of chlorine.
Q: What does PVC stand for?
Q: What are the products of the electrolysis of water?
Q: What is the chemical test for oxygen?
Q: What is an anode?
Q: What is a cathode?

6. A: Poly(chloroethene).
A: Regular medical evaluations; constant monitoring of worker exposure; use of protective clothing; use of breathing protection.
A: Chlorine is a green toxic gas. Exposure to as little as 1500 ppm in air can be fatal.
A: Poly(chloroethene).
A: Manufacture of bleach by reacting chlorine with dilute sodium hydroxide; treatment of water to kill bacteria; production of plastics like PVC by reacting chlorine with ethene.
A: A glowing wooden splint will relight in the presence of oxygen.
A: Hydrogen and oxygen (gases).
A: A negatively charged electrode.
A: A positively charged electrode.