- basically the better version of this
- Common properties
- Neutralisation Reactions
- What happens when acids react with…
- Footnotes and Other Notes
Hey there! Please be advised if you’re an boi this doesn’t exactly match your textbook! I’ve tried to keep similar concepts together so if you can’t find something, feel free to use the textbook, or use that neat little search bar up the top there! Thanks!
Acids are corrosive. They taste sour, and can be used to react with other substances.
Acids are chemicals with a pH < 7. Acids contain hydrogen ions (H⁺). When acids are diluted with water the concentration of H⁺ ions in the solution is reduced, and it’s pH increases towards 7 (neutral pH).
Bases are sometimes corrosive. They are bitter, slippery, and/or soapy. Bases that can be dissolved in water are called alkalis.
Bases are chemicals with a ph > 7. Bases contain hydroxide ions (OH⁻). When bases are diluted with water the concentration of OH⁻ ions in the solutions is reduced, and it’s pH decreases towards 7 (neutral pH).
Acids have a pH less than 7. Bases have a pH greater than 7. Remember it as
b. Acids come before bases on the pH scale.
|Acid name||Formula||Ionic Formula||PH Level|
|Hydrochloric acid||HCl||H⁺(aq) Cl⁻(aq)||2|
|Sulfuric acid||H₂SO₄||2H⁺(aq) SO₄²⁻(aq)||2|
|Nitric acid||HNO₃||H⁺(aq) NO₃⁻(aq)||2|
|Alkali name||Formula||Ionic Formula||PH Level|
|Sodium hydroxide||NaOH||Na⁺(aq) OH⁻(aq)||13|
|Calcium hydroxide||Ca(OH)₂||Ca2⁺(aq) 2OH⁻(aq)||13|
|Potassium hydroxide||KOH||K⁺(aq) OH⁻(aq)||13|
Water and neutral solutions has a pH level of 7.
You can test for how acidic or basic is using a number of ways. This includes using universal indicator to estimate pH, or test the reactivity of solutions in water.
When you mix an acid and a base together, a chemical reaction occurs! The mixture will get warmer and it usually follows this formula:
acid + base –> salt + water
Both metal oxides and metal hydroxides are bases
metal oxide + acid –> salt + water metal hydroxide + acid –> salt + water
When metal carbonates react with acids, they work the same way as metal oxides and hydroxides but on the reactant side there is also carbon dioxide gas
metal carbonate + acid –> salt + water + carbon dioxide
copper oxide + hydrochloric acid –> copper chloride + water CuO + 2HCl –> CuCl₂ + H₂O
Note how chloride in copper chloride on the reactant side has a subscript 2. This is to balance the chemical equation. As copper(II) has a valency of 2 we use the crossover method as covered in Chemistry 1 and multiplechloride by two. To balance the equation on both sides we add a 2 in front of
HCl which makes sure there are equal atoms on both the reactant and product side.
copper carbonate + nitric acid –> copper nitrate + water + carbon dioxide CuCO₃ + 2HNO₃ –> Cu(NO₃)₂ + H₂O + CO₂
When acids and bases react, they neutralise and produce salt and water.
When acids and metals react, they produce salt and hydrogen gas.
When acids and carbonates react, they produce salt, water and carbon dioxide.
Reactivity: tendency to lose or gain electrons
Reactivity of metal DECREASES from left to right, and INCREASES from up to down. Alkali metals in Group 1 have the highest reactivity, while noble gases in Group 8 are typically unreactive.
Acids and Bases on BBC Bitesize - https://www.bbc.co.uk/bitesize/guides/zsmgpbk/revision/2 ↩