C4 - Chemical calculations1️⃣✅ Flashcards
What is the conservation of mass?
That energy cannot be created or destroyed, just rearranged
What is a formula mass / Mr
Formula mass, Mr = the relative atomic masses of all the atoms in the formula
What are the 4 state symbols andwhat do they stand for?
(S)solid,(l)liquid,(g)gas and (aq)aqueous
How can you tell if a symbol equation is balanced?
If the number of atoms on each side are equal/ the same on both sides
What is a mole?
A mole is the relative atomic mass / formulas of any substance expressed in moles
What is the formula for working out moles?
Number of moles = mass (g)/ Mr
How do you work out the mass of A substance with only the Mr and moles?
You rearrange the formula to work out mass instead of moles. By doing this the formula would be mass = moles X Mr
What is a limiting reactant?
The reactant that is completely used up in a chemical reaction
How do you convert tons into grams?
Tons -> grams = x 1000000
How do you convert kilograms to grams?
Kilograms ->grams = X 1000
How do you convert milligrams to grams?
Milligrams -> grams = divide by 1000
What are the units for concentration?
G/dm3 or mol/dm3
What is the formula for concentration?
Concentration = moles/ volume( dm3)
How do you convert centimetres into decimetres cubed?
Centimetres -> decimetres = divide by 1000
In the concentration formula, what is the unit for volume?
Decimetres cubed (DM3)
What is theoretical yield?
The theoretical yields of a chemical reaction is the mass of a product that you expect to be produced
What is the yield?
The yield is the amount of product that you actually get in a chemical reaction
What is the formula for percentage yield?
Percentage yield = actual mass of product produced/maximum theoretical mass of product possible X 100
What is the formula for atom economy?
Atom economy = Mr of desired products/ Mr of all reactants x100
Why is a high atom economy desirable?
Because less waste is being produced/ more sustainable
What is atom economy?
A measure of the efficiency of a chemical reaction
What is the formula for the volume of a gas?
vol of gas = moles x 24
What is the unit of volume in the volume of gas formula?
dm3
What is the rearranged volume of gas formula with moles as the subject?
moles = vol of gas/24
