OCR CHEMISTRY A (FRI 21 MAY 10) EXAM NOTES

HideShow resource information

Notes on questions I got wrong:

  • Define relative atomic mass: LEARN EXACTLY

The weighted mean mass, of an atom of an element, compared to one-twelfth of carbon-12.

  • How do you find number of particles?

1) First do Mass/Mr to find the number of moles in the product.

2) Then times the number of moles by avogadro's constant.

Moles x (6.02 X 10^23)

  • How to find empirical formula:

1) Mass = percentage / Mr of each element

2) Amount = divide each amount calculated in (1) by the smallest amount calculated out of them.

3) Molar Ratio = try to get each answer calculated in (2) into an identifiable ratio e.g. 1:2

4) Formula = use numbers to construct formula using given compund name.

  • What are the 2 ions released when Sulfuric acid is in an aqueous solution?

Sulfuric Acid is H2SO4 in water it releases H+ and SO4 2- ions.

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Exam Questions resources »