Formulae
What is the relative formula mass of Mg(OH)2?
Mg=24, O=16, H=1
58
12 + [(16+1) x2]
What is Avogadro's number?
6.02 x1023
What is the standard molar gas volume at room temperature and pressure?
24dm3
Balance the following: Li + H2O --> LiOH + H2
2Li + 2H2O --> 2LiOH + H2
What is empirical formula?
Relative Atomic Mass, Ar, is compared to 1/12th of the mass of an atom of which element?
Carbon
How many molecules are there in 0.3 moles of N2?
1.8066 x 1023
Balance the following: Fe + O2 --> Fe2O3
4Fe + 3O2 --> 2Fe2O3
A sample of zinc chloride contains 12g Zn and 13g Cl. Calculate the empirical formula of zinc chloride.
ZnCl2
What is the percentage yield of a reaction if the actual yield of product was 27.3g and the theoretical yield was 32.3g?
84.5%
Calculate the concentration in dm3 of 25cm3 of 0.025 moles sodium hydroxide.
1.0 mol/dm3
Balance the equation for the complete combustion of propane.
C3H8 + 5O2 --> 3CO2 + 4H2O
.
A sample contains 79% of Mg-24, 10% of Mg-25 and 11% of Mg-26. What is the relative atomic mass?
24.32
Calculate the volume of O2 at RTP needed to react with 24g of CH4
CH4 + O2 --> H2O + CO2
72dm3
Calculate the maximum mass of iron that can be obtained from 500 tonnes of iron oxide (Fe2O3).
349.72 tonnes
What is the atom economy of extracting iron from its core?
Fe2O3 + 3CO --> Fe + 3CO2
45.8%
0.010 dm3 of 0.25 mol/dm3 nitric acid reacts with 0.013dm3 of 0.30 mol/dm3 KOH solution. Which reactant is in excess?
HNO3 + KOH --> H2O + KNO3
KOH (Potassium Hydroxide)
Calculate the number of moles of C16H12N2O in a 0.50g sample.
0.0020 moles
27.20cm3 of NaOH solution was titrated with 25.00cm3 of a 0.75mol/dm3 HNO3 solution. What is the concentration of the NaOH??
0.69 mol/dm3
If there are 0.3 moles of HCl, what mass of calcium carbonate would be required for a complete reaction?
CaCO3 + 2HCl --> CaCl2 + H2O + CO2
15.01g