SC8 - Acids and Alkalis Flashcards
What is an acidic solution?
what is an alkali solution?
What is the pH scale?
What are the acid-alkali indicators?
What are the corresponding colours for each indicator in acids, alkalis and neutral solutions?
Indicator - Acidic - Neutral - Alkaline
Litmus paper - Red - Purple - Blue
Methyl orange - Red - Yellow - Yellow
Phenolphthalein - Colourless - Colourless - Pink
Describe the limitations of methyl orange when determining if a solution is alkaline.
Describe the limitations of phenolphthalein when determining if a solution is acidic.
What is produced in excess when acids are dissolved in water? Give an example of this happening,
What is produced in excess when alkalis are put in water? Give an example.
How does the concentration of hydrogen/hydroxide ions affect acidity?
Exam Q -
Explain why the pH of a hcl acid increases when pure water is added. (2 marks)
What would happen to the pH of a salt solution ( pH 7) if pure water was added ? (2 marks)
What is the equation for concentration using volume and amount dissolved?
concentration = amount dissolved / volume
How does a change in pH affect the concentration of hydrogen ions in an acid?
What is dissociation in acids, give the 2 types and how does each one affect the strength of the acid?
What are bases and what do they form?
What is the equation of neutralisation reaction?
What happens during neutralisation?
What is the method of preparing soluble salts for example when you obtain tin chloride from hydrochloric acid and tin oxide?
Magnesium nitrate can be made by reacting magnesium oxide with an acid.
a. Which acid?
b. Why should the acid solution be warmed slightly?
c. Why is the magnesium oxide added in excess?
d. Why is the mixture filtered?
e. Why is the salt solution heated?
Describe the practical for preparing copper sulfate.
What is a base which can dissolve in water?
Give 2 examples of soluble bases.
When alkali bases react with acids to produce salt and water, what is the equation?
Describe the core practical for investigating neutralisation.
How do you obtain soluble slats from alkalis?
What is titration?
What is seen as hydrogen gas bubbles are produced when metals and acids react?
What is the equation for metals and acids reacting?
Hydrogen is collected in a test tube during the reaction between magnesium and hydrochloric acid. Describe the laboratory test for hydrogen.
Put a lighted splint near the mouth of the test tube. Hydrogen ignites with a squeaky pop.
What is the equation for when acids react with carbonates?
Carbon dioxide is given off during the reaction between copper carbonate and hydrochloric acid. Describe the laboratory test for carbon dioxide.
Bubble the gas through limewater Carbon dioxide turns limewater milky or cloudy white.
Key fact:
Metal oxides and metal hydroxides both react with acids to produce salts and water.
Explain why gold sulfate isn’t formed when gold is added to dilute sulfuric acid.
What are spectator ions?
Chloride and nitrate ions are spectator ions. The ionic equation is:
2H⁺ + CO3²⁻ → H20 + CO2
Write the ionic equation for the reaction between magnesium carbonate and hydrochloric acid.
What is oxidisation?
What is reduction?
What does OIL RIG stand for?
What is the test for CO2?
Exam Q -
Describe a test to show a gas is hydrogen. (2 Marks)
What is precipitation?
What substances are insoluble?
What substances are soluble?
Write the equation for the CO2 test.
Describe a method to prepare insoluble salts.
