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level: Acids & Bases: pH

Questions and Answers List

level questions: Acids & Bases: pH

QuestionAnswer
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 concentrationa 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 dissociationbreaking 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 acidspH<7
What is the PH range of alkalispH>7
what is the pH of neutral solutionspH=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