C4- Chemical calculations

6.02x10 to the power of 23

Relative mass of an atom compared to the C-12 atom

The sum of all the relative atomic masses in a compound

Moles=mass/ Ar or Mr

The relative formula mass in grams

The reactant that is used up first in a reaction

actual mass of product/theoretical mass of product x 100

The mass of product that a chemical reaction produces

-Reaction may be reversible -Some product may be left on apparatus -Some product may be lost in separation from mixture

-Conserves Earth’s resources -Helps company make more money as less wasted energy and reactants -Reduces pollution produced

Relative formula mass of wanted product/ sum of relative formula masses of reactants x 100

Amount of solute (g) / volume of solution(dm3)

0.001dm3 1000cm3

-Add more solute to the same volume -Evaporate some water, lower volume, same mass

To accurately measure what volumes of acid and alkali react completely

The point at which the acid and alkali have reacted completely

-Use pipette and pipette filler, measure a known volume of alkali into a conical flask -Add a few drops of indicator, place on white tile and swirl -Pour the acid into the burette, record volume -Slowly allow acid into conical flask, swirl, until solution changes colour -Calculate volume of acid used, repeat until the results are concordant

Two titres within 0.1cm3 of each other

Concentration= moles/volume

Moles of gas = volume of gas / 24dm3

24dm cubed