| why is pure water neutral? | there is an equal concentration of hydrogen and hydroxide ions |
| why is pure water neutral? | there is an equal concentration of hydrogen and hydroxide ions |
| soluble metal oxides dissolve to form what? | metal hydroxides / alkalis |
| What does the pH scale measure? | the concentration of hydrogen ions present in a substance |
| what is pH? | a measure of the hydrogen ion concentration of a solution |
| if a substance produces H⁺(aq) ions what is it? | An acid |
| If a substance produces OH⁻(aq) ions what is it? | An alkali |
| What happens when you dilute an acid? | the pH increases towards 7
concentration of hydrogen ions decreases |
| What happens when you dilute an alkali? | the pH decreases towards 7
concentration of hydroxide ions decreases |
| What is concentration | a measure of how much solute is dissolved in a given volume of solution, in mol l-1 |
| what is an electrolyte? | liquids which conduct electricity |
| water has a covalent molecular structure but still contains some ions, how come? | from the dissociation of a few water molecules |
| define dissociation | breaking up |
| what do water molecules dissociate into? | 1 H⁺ ion and one OH⁻ ion. |
| What is the equation for the dissociation of water? | H₂O(l) ⇌ H⁺(aq) + OH⁻(aq) |
| What is a base? | a substance which neutralises acids forming a salt and water |
| What are the three (+1) types of bases? | metal oxides
metal hydroxides
metal carbonates
ammonia |
| how are metal oxides formed? | when a reactive metal reacts with oxygen |
| what type of substances are metal oxides? | ionic substances |
| soluble metal oxides dissolve to form what? | metal hydroxides / alkalis |
| what is the pH range of acids | pH<7 |
| What is the PH range of alkalis | pH>7 |
| what is the pH of neutral solutions | pH=7 |
| why does pure water have a very low conductivity? | it contains a very low concentration of hydrogen and hydroxide ions |
| why is pure water neutral? | there is an equal concentration of hydrogen and hydroxide ions |
| what does this symbol mean in a chemical equation?
⇌ | the reaction is reversible
it can occur in both directions |
| how do you dilute an acid or alkali by a factor of 10? | Half fill test tube with acid/alkali and add universal indicator
use dropper to remove 1cm^3 into a measuring cylinder. Add water to make up it up to 10cm^3. Pour this into another test tube.
Remove 1cm^3 of acid/alkali from test tube 2 into measuring cylinder and make up to 10cm^3 with water. Pour this into a third test tube.
Repeat this. |
| what do soluble non-metal oxides dissolve in water to form? | acidic solutions |
| SO₂(g) + H₂O(l) → 2H⁺(aq) + SO₃²⁻(aq)
In this reaction, sulfur dioxide reacts with water. What is formed? | sulfurous acid |
| where can you find the solubility of metal oxides? | solubility table data book pg 8 |
| What is the ionic formula for hydrochloric acid? | H⁺Cl⁻ |
| What is the ionic formula for sulfuric acid? | (H⁺)₂SO₄²⁻ |
| What is the ionic formula for Nitric Acid? | H⁺NO₃⁻ |
| What is the ionic formula for Potassium hydroxide? | K⁺OH⁻ |
| What is the ionic formula for Sodium Hydroxide? | Na⁺OH⁻ |
| What is the ionic formula for Lithium Hydroxide? | Li⁺OH⁻ |
| What is the ionic formula for Calcium hydroxide? | Ca²⁺(OH⁻)₂ |
| what do bases that dissolve in water form? | Alkaline solutions |
