Chemistry- Topic 3: Quantative chemistry

conservation of mass

atoms cannot be made or lost in a reaction

relative atomic mass

relative mass of an atom compared to carbon-12

formula mass

• Mr

• sum of all the atomic masses of aof the atoms in a compound

uncertainty

the liklihood that our readings are accurate

How do we measure uncertainty?

resolution: + or - o.5 of resolution

range: + or - 0.5 of range

percentage yield

• efficiency of reaction

• how much product we made v how much we were expecting to make

percentage yield equation?

actual yield ÷ theoretical yield x 100

atom economy

• how mnay atoms turned into something useful v how many atoms there were in total

atom economy equation?

Mr of desired products ÷total mr of all reactants x 100

What does the co-efficient in an equation tell us?

the relation between the substances, the molar ration

What is a mole?

• The amont of a substance that contains avregados number

• -6.02 × 10²³

• one mole of anything will ahve the same mass as its mass number

what is the mole equation?

number of moles = mass ÷Mr

What are limiting reactants?

• when this substance runs out the recation is over, less than the molar ratio, some of the other reactants may be left over

What is avregadoes other rule (gas)

• 1 mol of any gas takes up 24dm of space

What is solvent and solute?

• Solvent : does the dissolving

• Solute : the thing that gets dissolved

Concentration?

• the amount of a substance dissolved in a certain volume of solution

• Often given in dm³ (1 litre/ 1000cm)

Concentration equation?

Mass ÷ volume

Molar gas equation?

Moles of gas = volume (dm³) ÷ 24

Concentration equation with moles

No. Moles = concentration x volume