Download Hydrogen gas is produced when magnesium is added to dilute

CHEMICAL CALCULATIONS WEEK 7 (TEACHER
EXAMPLE RED)
Hydrogen gas is produced when magnesium is added to dilute
hydrochloric acid.
Mg + 2HCl --------- MgCl2 + H2
What volume of gas is produced when 0.6 moles of the acid is used
completely?
The lab prep for oxygen requires hydrogen peroxide and the catalyst
manganese dioxide
2H2O2 ------------
2H2O + O2
25mL of oxygen gas is produced during an experiment. How many moles of
hydrogen peroxide has decomposed?
Carbon dioxide is made by adding hydrochloric acid to calcium carbonate. A
teacher requires 150mL at NTP. How g of calcium carbonate should he use?
CaCO3 + 2HCl -------- CaCl2 + H2O + CO2
EXTRA QUESTIONS
Q1 Hydrogen sulphide H2S gas can be made by adding sulphuric acid to iron
sulphide. (FeS) Iron sulphate is also produced during this reaction.
If 4 moles of iron sulphide is used what volume of gas will be produced at STP?
Q2 A technician requires 500mL of laughing gas (N2O). How many moles of
ammonium nitrate should be decomposed to produce this?
NH4NO3 --------
N2O + 2H2O
Q3 500Kg of old car panels need to be dissolved in sulphuric acid. Assuming
that the car panels are steel (mainly iron) How many moles of sulphuric acid is
required for this job?
Fe + H2SO4 --------
FeSO4 + H2
Q4 Copper metal can be extracted from copper oxide CuO by simply heating
it with carbon powder C. If 750g of copper is required, how many g of copper
oxide should be treated with carbon. What volume of carbon dioxide will be
produced during this process? (NTP conditions)
Chemical calculations H Graham BSc PGCE