Calculations using reacting masses Flashcards Preview

Topic 5.2 (Amount of substance) > Calculations using reacting masses > Flashcards

Flashcards in Calculations using reacting masses Deck (6)
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1
Q

a balanced equation not only shows the same number of each species on both sides, but is also balanced

A

for the masses of each species

2
Q

we can use balanced equations to work out

A

amounts of substances

3
Q

we can use the……….in balanced equations to work out the amounts of substances

A

ratios of the species

4
Q

the 4 steps for working out amounts of substances are: (generically)

A

1) work out the molar masses of the substances you are told about and asked about
2) calculate the amount (moles) of the substance you are told about (i.e. have been given the mass)
3) use the reaction ratio in the equation to work out the amount (moles) of the substance you ‘want’
4) Now use n=m/M to calculate the mass of the substance you are asked for

5
Q

sometimes, there are two or more possible

A

reactions for the same reactants, so the reacting masses can be used to identify which of the reactions is occurring

6
Q

hydrates are

A

compounds containing water of crystallisation, represented by formulae such as CuSO4.5H2O