12 Days of Chemical Calculations – 10
A student set out to make some copper (II) oxide from copper (II) sulphate. He took 20.0 cm3 of 0.400 mol dm3 dm-3 copper (II) sulphate solution, added an excess of sodium hydroxide to give […]
GCSE
12 Days of Chemical Calculations – 8
Calculations involving solutions 25.0 cm3 of 0.04 mol dm-3 sodium hydroxide solution reacted with 20.75 cm3 of sulphuric acid in a titration. Give the chemical equation for the reaction and find the concentration of the […]
12 Days of Chemical Calculations – 7
Calculations involving solutions What volume of 0.1mol dm-3 hydrochloric acid would react with 25 g of calcium carbonate and what volume of gas would be produced? CaCO3 + 2 HCl –> CaCl2 + CO2 + H2O
12 Days of Chemical Calculations – 6
Mole calculations The reaction below is known as the Thermite reaction, which is used to form molten iron to mould iron train tracks together. What mass of aluminium powder is needed to react with 8.0 […]
12 Days of Chemical Calculations – 5
Mole calculations What mass of carbon monoxide is needed to react with 1 kg of iron oxide? Fe2O3 + 3 CO –> 2 Fe + 3 CO2
12 Days of Chemical Calculations – 4
Empirical & Molecular Formula A compound containing carbon, hydrogen & oxygen only, contains 74.2% carbon and 7.9% hydrogen. Its Mr is found to be 178 by mass spectroscopy. Find its empirical and molecular formulae
12 Days of Chemical Calculations – 3
Empirical Formula A compound contains 59.4% carbon, 10.9% hydrogen, 13.9% nitrogen and 15.8% oxygen by mass. Find the empirical formula of the compound…
12 Days of Chemical Calculations – 2
Amount of substance Find the number of moles present in the following 12g Carbon12 32g Water (H2O) 50g Magnesium 100g Iron (III) Oxide (Fe2O3) 1,250 tonnes Iron (III) Oxide (Fe2O3) Find the mass of substance when […]
12 Days of Chemical Calculations – 1
Merry Christmas to all Chemstuff followers! Over the next 12 days get ready for 12 christmas presents of chemical calculations (You can’t say I never treat you to anything!) Please show your working as much […]
The Nobel Prize in Chemistry 2012
This year’s Nobel prize for chemistry has just been announced. The Nobel prize is an award for a piece of research or work over a period of time which has changed the way scientists think about their […]
