quantitative chemistry

Question 1

how to find relative formula mass (Mr)

Answer 1

find the relative atomic mass (Ar) of all the elements in the compound

add it all up

e.g MgCl2

Mg: 24
Cl: 35.5

MgCl2 = (2x35.5)+24 = 95

Question 2

percentage mass formula

Answer 2

relative atomic mass (Ar) x number of atoms/relative formula mass of compound (Mr)
x 100

Question 3

mols formula

Answer 3

mass of an element (g)/relative formula mass (Mr)

Question 4

when given the mass + elements, how do you create a balanced symbol equation

Answer 4

divide each substance by the relative formula mass (Mr)

divide the number of each mol by the smallest mol in the equation

if numbers arent whole, multiply them all by the same number to make it so. other than that, write an equation!! :D