Search our library of GCSE questions

Top answers

All subjects

GCSE

Jay, Shelia & Harry share £7200 in the ratio 1:2:5. How much does Harry receive?

Explain how the ratio shows everyone's share of the £7200: 1:2:5 (Jay's share:Sheila's Share:Harry's Share)Add up the terms of the ratio to find out many equal parts the £7200 is split into: 1+2+5=8 (part...

Answered by Philip B. • Maths tutor

4296 Views

A ladder of length 6.5m is leaning against a vertical wall. The foot of the ladder is 1.5m from the wall. Calculate the distance the ladder reaches up the wall to 3 significant figures.

(using Pythagoras' theorem) 6.5²= x²+ 1.5²x²= 6.5²- 1.5²x²= 42.25 - 2.25 x² = 40 x = sqrt(40) x ...

Answered by Pollyanna B. • Maths tutor

6098 Views

Zinc reacts with sulphuric acid (Zn + H2SO4 --> ZnSO4 + H2). Write out two separate equations for the species that are oxidised and reduced.

Zn --> Zn^2+ + 2e- (OXIDATION) H2^2- + 2e- --> H2 (REDUCTION)

Answered by Sonali V. • Chemistry tutor

16797 Views

Name the 3 structures within a plant cell that are absent from an animal cell and describe the function of these 3 structures. (6 marks)

Plant cells contain chloroplasts (1), a cell wall (1) and a permanent vacuole (1). These structures are absent from animal cells. Chloroplasts contain chlorophyll which abso...

Answered by Hannah L. • Biology tutor

8537 Views

A student wanted to make 10.0 g of zinc chloride. The equation for the reaction is: ZnO(aq) + 2HCl(aq) → ZnCl2(aq) + H2O(l) Calculate the mass of zinc oxide the student needs to react with the dilute acid to make 10.0 g of zinc chloride. [4 marks]

What do we know from the question? 1. we know the balanced equation 2. we know the mass of zinc chloride we want to form. using the equation number of moles = mass/Mr we can calculate the number of moles ...

Answered by Arun S. • Chemistry tutor

8283 Views