Maths Stuff And Rate Of Reaction

Question 1

% yield.

Answer 1

Actual mass / theoretical mass x 100

Question 2

Mole calculations.
Mg + 2HCl -> MgCl2 + H2
What mass of Mg is able to react with 3g of HCl?

Answer 2

Work out the no. of moles of what you have a mass of:
no. of moles = mass / Mr
= 3 / 36.5
= 0.0822

Look at the ratio
0.0822 / 2 = 0.0411 moles of Mg

Work out the mass you need:
no. of moles = mass / Mr
mass = no. of moles x Mr
= 0.0411 x 24
=0.986g