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Acids and bases:. Reactions. DON’T COPY pink WRITING. Acid + base. This is a common reaction and needs to be remembered for exams. ACID + BASE -> SALT + WATER E.g. hydrochloric acid + sodium hydroxide -> sodium chloride + water HCl + NaOH -> NaCl + H 2 O. Experiment:.
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Acids and bases: Reactions. DON’T COPY pinkWRITING
Acid + base • This is a common reaction and needs to be remembered for exams. • ACID + BASE -> SALT + WATER • E.g. • hydrochloric acid + sodium hydroxide -> sodium chloride + water • HCl + NaOH -> NaCl + H2O
Experiment: • Aim: to make a salt by reacting an acid and a base • Method: • Place 1 mL of 1 molL-1 sulfuric acid into a test tube • Place 2 mL of 1 molL-1 sodium hydroxide into the same test tube. • Gently shake and tip into an evaporating dish. • Make a label and place the evaporating dish on the window sill.
Results: • When we mixed the chemicals we saw … (leave a whole line) • After the evaporating dish had been left on the window sill we saw … (leave a whole line) • Conclusion: • Acid + base -> salt + water • Sulfuric acid + sodium hydroxide -> sodium sulfate + water • H2SO4 + 2NaOH -> Na2SO4 + 2H2O
Acid + carbonate • This is a common reaction and needs to be remembered for exams. ACID + CARBONATE -> SALT + WATER + CARBON DIOXIDE • E.g. • Hydrochloric acid + calcium carbonate -> calcium chloride + water + carbon dioxide • 2HCl + CaCO3 -> CaCl2 +H2 O + CO2
Experiment: • Aim: to observe an acid and a carbonate experiment. • Method: • Place 2 small pieces of marble in the bottom of a test tube • Add 3 mL of sulfuric acid • Write down your observations • Results: What did you see happen, what did you hear or feel? Leave a whole line
Conclusion: • An acid + a carbonate produces a gas. This gas is carbon dioxide gas. • Acid + Carbonate -> salt + water + carbon dioxide H2SO4 + CaCO3 -> CaSO4 + CO2 + H2 O
Acid + Metal • An acid + metal reaction produces hydrogen gas and a salt. • ACID + METAL -> HYDROGEN GAS + SALT • E.g. • Hydrochloric acid + zinc -> hydrogen gas + zinc chloride • 2HCl + Zn -> H2 + ZnCl2
Experiment • Aim: to observe a reaction between an acid and a metal • Method: • Place a piece of magnesium metal in the bottom of a test tube • Add 3 mL of sulfuric acid • Write down observations • Results: • What did you see, hear or feel? Leave whole line
Conclusion: • An acid and a metal produces hydrogen gas. • H2 SO4 + Mg -> MgSO4 + H2
formula Name chemical substances from their formula and write simple word equations
TASK: stick in the ions handout For each of the following give the name of the chemical • NaCl • H2O • NaOH • Ca(OH)2 • MgCl2 • MgSO4 • CuCO3 • NaHCO3 • Na2CO3 • Sodium chloride • Water • Sodium hydroxide • Calcium hydroxide • Magnesium chloride • Magnesium sulfate • Copper carbonate • Sodium hydrogen carbonate • Sodium carbonate
Ions and their names: highlight these on the handout, add new ones • Sulfate • Carbonate • Chloride • Fluoride • Nitrate • Iodide • Hydroxide • oxide • SO42- • CO32- • Cl- • F- • NO3- • I- • OH- • O2-
Balancing compounds • When you are trying to work out the formula for a compound, you need to balance the ion charge. It’s a bit like a fraction (1/2 + 1/3) • If one of the ions is +1 and the other is -1 it is easy. If one of the ions is +2 and the other is -1 it gets a bit more complicated. • The hardest is e.g. +3 and -2. • Na is +1 and SO4 is -2; this means we need 2 X Na to balance the -2 charge: Na2 SO4 • If Cu is +2 and OH is -1; this means we need 2 X OH to balance the +2 charge: Cu(OH)2 . We have to put brackets around the OH because we need 2 of the hydroxide ion, if we wrote it CuOH2 it would just mean there were 2 H’s.