filtration used to separate an insoluble solid from a liquid. crystallisation is used to separate a solouble solid from a solution. You can use filtration and crystallisation to separate rock salt. Acid+Metal=Salt+Hydrogen. the name of the salt depends on the metal and acid used. Metals also react with water (metal+water=metal hydroxide+hydrogen) very reactive (potassium,sodium,lithium,calcium) fairly reactive (magnesium,aluminium, zinc) not very reactive(iron, copper)not at all reactive(silver, gold) The atomsphere is mostly nitrogen and oxygen (78%nitro.21%oxy) You can investigate the proportion of oxygen in the atmosphere using copper (2Cu+O2=2CuO) O2 in a lab(2H2O2(aq)=2H2O(l)+O2(g)) When you burn something it reacts with ox. In the air. magnesium: 2Mg(s)+O2(g)= 2MgO(g) carbon: C(s)+O2(g)=CO2(g) sulfur: S(s)+O2(g)=SO2(g) Dilute acid reacts with calcium carbonate to produce carbon dioxide 2HCl(aq)+CaCo3 (s)=CaCl2(aq)+H2O(l)+CO2(g) Thermal descomposition of metal carbonates also producesCO2 (CuCo3(s)=CuO(s)+CO2(g) COs used in fizzy drinks and fire extingushers. Its a green house gas (insulating layer) Chlorine:bleaches damp litmus paper, turning it white. oxygen:relights a glowing splint carbondioxide:turns lime water cloudy. Hydrogen:makes squeaky pop with a lighted splint. ammonia:turns damp red litmus paper blue. Acids react with metal oxides to make salt and water (acid+metaloxide=salt+water) and with water to give salt+water+carbondioxide. (acid+metal carbonate= salt+water+carbondioxide) Rates of reaction= temp, concentration, catalyst, size of particles.