Daily Practice · GCSE Science

Daily Practice - GCSE Science

Biology, chemistry and physics recall, definition and calculation, drawn from every strand.

18th July 2007

5 questions · GCSE · 584 questions in this band

1
Concentration, Yield and Atom Economy
Give the formula for atom economy.
2
Chemical Changes
A student reacts 2.4 g of magnesium with excess dilute hydrochloric acid: Mg + 2HCl -> MgCl2 + H2. Relative atomic mass of Mg = 24. Calculate the number of moles of hydrogen gas produced.
3
Reactivity, Acids and Salts
Why is aluminium extracted by electrolysis rather than by reduction with carbon?
4
Electrolysis
In the industrial extraction of aluminium, explain why the carbon anodes need to be replaced regularly.
5
Energy Changes
A reaction profile shows the reactants at 220 kJ and the products at 340 kJ. State whether the reaction is exothermic or endothermic.

You are looking at an earlier sheet. Today's sheet is the one that adds a day.

Your run is kept in this browser only, and there is no account.

Every sheet is deterministic: the same date always regenerates the same five questions. All of July 2007, including the monthly compilation PDF.