GCSE Chemistry: Year 10: C3 Quantitative Chemistry

Everything on the checklist

What is the law of conservation of mass?

No atoms are lost or made during a chemical reaction so mass of products = reactants

What is Mr?

Mr stands for relative molecular mass

What is RFM?

RFM stands for relative formula mass, which is the sum of the relative atomic masses of all atoms in a chemical formula.

What does the RAM tell us?

The mass of a single atom of an element

Balance Cu + O2 —> CuO

2Cu + O2 —> 2CuO

What is the Mr of ethanol? (C2H6O)

46

What reactions appear to involve a change in mass?

Mg + O2 —> 2MgO, mass seems to increase

Why does mass increase for Mg+O2 —> 2MgO?

Because initially the oxygen is not weighed as you cannot measure the mass of a gas in the air; and the magnesium is reacting with oxygen from the air.

What does measurement uncertainty mean?

The margin of doubt that exists for any measurement; written as ± measurement (e.g. 20cm ± 1cm)

How to calculate measurement uncertainty on a measuring cylinder?

Smallest division/ 2

What is the symbol for the unit mole?

mol

What is the value for the Avogadro constant?

6.02 × 10²³

What is a mole?

6.02 × 10²³ of something

How to find number of moles?

Moles = Mass in g / RAM or RFM

What is 1 mole of a substance in grams equal to?

Its RFM

Calculate the number of moles of 66g of calcium

1.65 mol