1. What is an ion? What is copper sulphate? What is copper?What is sulphate? When an atom loses or gains one or more electrons it becomes an ion. An ion either has a positive or negative charge depending on whether it has gained or lost electrons. Copper sulphate is an ionic compound (made of ions) made of copper, oxygen and sulphur. It is blue in colour and comes from an ore called malachite. Copper is a conducting metal and is used for electrical wire and plumbing. Copper atoms lose electrons to become a positive ion. Sulphate is a negative ion made of oxygen and sulphur. The bond between the oxygen and sulphur is not easily broken and therefore it remains together as a sulphate ion.

2. What do electrodes do? What happens when you add water? What is electrical current?Why is charge important? Electrodes are electrical conductors which when connected to a power source become positively or negatively charged. Carbon is often used for electrodes due to it’s conducting properties. Positive charges are attracted to negative charges. Negative charges are attracted to positive charges. opposites attract When ionic compounds are dissolved in water, the ions become free from each other. Electrical current is the flow of charge in a particular direction. Metals are good conductors because they have free electrons which have a negative charge. Ions also carry charge because they have lost or gained electrons.

3. copper ionssulphate ionshydrogen ionshydroxide ions Cu 2+ SO 2- H+H+ OH - When copper sulphate is dissolved in water it becomes a solution of four different ions. What ions does copper sulphate solution have? 4 What is water? Which ions are left at the electrodes? When two ions of the same charge are attracted to an electrode, they compete to stay in the solution. Similarly to extraction by reduction method, the less reactive ion is isolated (reduced) and left at the electrode. Water is an ionic compound made of hydrogen and hydroxide ions. Hydrogen ions have a positive charge. Hydroxide ions have a negative charge. Hydroxide ions are made of oxygen and hydrogen chemically bonded together. Sulphate ions do not give up their extra electrons easily and therefore it is hydroxide ions that are oxidised at the electrode. What is sulphuric acid? Sulphuric acid is an ionic compound of hydrogen and sulphate ions. The positive hydrogen ions give acid it’s acidity. Sulphate and hydroxide are not on the reactivity series.