SC8 Flashcards
(19 cards)
What is the pH range for acids and alkalis?
Acids: 0-6, Alkalis: 8-14, Neutral: 7
What colour does litmus turn in acid and alkali?
Alkali: Blue Acid: Red
What is a universal indicator?
A mixture of dyes that shows pH as a range of colours
What ions do acids release in water?
H⁺ ions (hydrogen ions)
What is the difference between a strong and weak acid?
Strong acids completely ionise (e.g., HCl), weak acids partially ionise (e.g., CH₃COOH)
What is a base?
A substance that neutralises an acid (metal oxides/hydroxides)
What is the general word equation for acid + base?
Acid + Base → Salt + Water
What is the general word equation for acid + metal?
acid + metal → salt + hydrogen
What is the general word equation for acid + metal carbonate?
acid + metal carbonate → salt + water + carbon dioxide
What salt is produced in HCl + NaOH?
Sodium chloride (NaCl)
How would you make pure copper sulfate crystals?
React sulfuric acid with copper oxide
Filter excess oxide
Evaporate and crystallise
Why is excess copper oxide used?
To ensure all acid reacts (indicated by solid remaining after reaction)
What ions do alkalis release in water?
OH⁻ ions (hydroxide ions)
How would you investigate temperature change in neutralisation?
- Mix acid and alkali
- Measure max temperature reached
- Repeat with different concentrations.
What gas is produced when acids react with metals?
Hydrogen (test with squeaky pop)
What is the test for carbon dioxide?
Bubble through limewater → turns cloudy
Are nitrates soluble?
Yes, all nitrates are soluble
Are sulfates soluble?
Mostly yes, except barium/lead/calcium sulfate
How do you predict precipitation?
Step 1: Identify the ions in the reactants that are present
Step 2: Swap ions to form possible products.
Step 3: Check solubility rules—if any product is insoluble, precipitation occurs
