Topic 2- Acids, Alkalis and bases Flashcards
(21 cards)
What does an acid do?
They produce hydrogen ions H+ when they dissolve in water
What does an alkali do?
Alkalis produce hydroxide ions, OH- when they dissolve in water.
What is the word equation for an acid reacting with a metal?
Metal + Acid -> Salt + Hydrogen
How do you name a salt?
name of metal - acid (ate, ide)
What are bases usually?
oxides or hydroxides of metals
What are bases that are soluble in water called?
Alkalis
What do bases and alkalis end in?
Bases- Oxide Alkali- Hydroxide
what is neutralisation?
When an acid reacts with a base, canceling each other out to form a neutral product.
How does neutralisation work in an equation?
The H+ ions from the acid react with the OH- ions from the alkali to form water.
H+(aq) + OH-(aq) -> H2O(I)
What is the equation for acids reacting with carbonate?
Acid + metal carbonate -> salt + water + carbon dioxide
What is titration?
The method used to prepare crystals of soluble salts from the reactions of acids and alkalis.
What are the steps of titration?
1) Indicator and a fixed volume of acid/alkali in a flask.
2) Exact volume of alkali/ acid needed for neutralisation is measured and recorded.
3) same fixed volume of acid/alkali in clean flask and exact volume of acid/ alkali needed for neutralisation is added but with NO indicator.
4) Evaporation of water to form crystals.
What is the test for sulfate ions?
Add barium chloride, white precipitate if present.
Ba2 + SO4 2- -> BaSO4
What is the test for carbonate ions?
Add acid, effervescence turn limewater cloudy.
Acid + carbonate -> Salt + water + CO2
What is the word equation for acids reacting with bases (oxide)?
Acid + oxide -> Salt + water
What is the word equation for an acid reacting with an alkali (hydroxide)?
Acid + hydroxide -> salt + water
Why is the pH of acids lower if they are strong?
They have a higher concentration of hydrogen ions.
What is the difference between strong acids and weak acids?
Strong acids are fully ionised, but weak acids are partially ionised in solution.
What is the strength of an acid defined by?
The measure of the degree of its ionisation.
What is the concentration of an acid defined by?
The number of moles of an acid in 1dm/3 of acid solution.
What does a weak acid form when they do not fully ionise?
An equilibrium mixture.
