# CGPwned: Molar Calculations Crash Course!

I don't think this includes electrolysis calculations but you can find that by downloading Chemistry CGPwned :)

Anyways hope this helps with those who have trouble doing molar calculations!

- Created by: cgpwned
- Created on: 14-03-12 13:08

First 216 words of the document:

Do it...the CGPwned Way!:)

MOLAR CALCULATIONS THE CRASH COURSE

A mole is a measure of the amount of substance. One mole contains 6 x 1023 (also known as

the Avogadro Number) particles (atoms, molecules or formulae) of the substance. For example,

1 mol of sodium contains 6 x 1023 atoms of sodium.

CALCULATING RELATIVE ATOMIC MASS

Chlorine has two isotopes: chlorine-35 and chlorine-37. A typical sample will be 75%

chlorine-35 and 25% chlorine-37.

The RAM = (0.75 x 35) + (0.25 x 37) = 35.5g

CALCULATING RELATIVE FORMULA MASS

H2 Hx2 2x1=2

Ca(OH)2 (1 x Ca) + (2 x O) + (2 x 40 + (2 x 16) + (2 x 1) =

H) 74

CALCULATING THE NUMBER OF MOLES IN A GIVEN MASS OF AN ELEMENT/COMPOUND

Amount in Mass

moles =

RFM

Amount in moles = Mass of Substance (g) /RFM of Element or Compound (g)

a) Calculate the number of moles in 2.3g of sodium:

RFM of sodium = 23g per mole

Given mass = 2.3g

Amount in moles = 2.3g / 23g

= 0.01 mol

b) Calculate the mass of 2 moles of magnesium:

RFM of magnesium = 24g per mole

Given mass = x

Given moles = 2 mol

2 mol = x / 24g

x = 2mol x 24g

= 48g

SIMPLE MOLAR CALCULATIONS

Chemical equations are like, ratios. For example:

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