What happens to the pH during a neutralisation reaction?
It moves toward pH 7
What effect does increasing temperature have on reaction rate?
Increases the rate
Which group of salts is always soluble?
Sodium, potassium, ammonium
According to proton theory, what do acids release?
Protons (H⁺ ions)
What colour does litmus turn in an alkali?
Blue
Why does adding more surface area of a carbonate increase reaction speed with an acid?
More particles are exposed for collisions
Why does increasing concentration speed up reactions in solution?
More particles per volume → more collisions
What separation step is needed after reacting acid with excess insoluble base?
Filtration to remove unreacted solid
Why does a weak acid have a higher pH than a strong acid of the same concentration?
It only partially dissociates, producing fewer H⁺ ions
Which ion increases as a solution becomes more acidic?
H⁺ ions
CO₂ is produced when acid reacts with carbonates — how could you confirm this gas?
Bubble it through limewater and observe milky appearance
Why does powdered solid react faster than a lump?
Larger surface area increases collision opportunities
Why can’t you use precipitation to make a soluble salt?
Because the product would not separate from solution
Which acid in the syllabus is weak and only partially ionises?
Ethanoic acid
Why does phenolphthalein only turn pink in alkaline solutions?
Because it changes colour only when OH⁻ ions are present
Explain why amphoteric oxides are difficult to classify as acidic or basic.
Because they react with both acids and bases
Why does increasing gas pressure increase rate?
Particles are closer together → more collisions
Which salts are soluble except for lead and silver?
Chlorides
Why are strong acids better electrical conductors than weak acids?
More ions are present in solution
Why does universal indicator give more information than litmus?
It shows a range of colours linked to approximate pH
Explain why hydrochloric acid is considered strong even when diluted.
Because it completely dissociates into ions regardless of concentration
Explain how a catalyst speeds up a reaction using collision theory.
It lowers activation energy, so more collisions are successful
Why do carbonates of most metals form precipitates in water?
Because they are insoluble except sodium, potassium, ammonium
Explain why hydrochloric acid is considered strong even when diluted.
Because it completely dissociates into ions regardless of concentration
Explain the link between hydrogen ion concentration and strength of acidity.
Higher concentration of H⁺ ions means stronger acidity