|1.||The octane present in gasoline burns according to the following equation:|
|2 C8H18 + 25 O2 ---------------> 16 CO2 + 18 H2O|
|(a) How many moles of O2 are needed to react fully with 4 moles of octane?|
|(b) How many moles of CO2 can form from 1 mole of octane?|
|(c) How many moles of water are produced by the combustion of 6 moles of octane?|
|(d) If this reaction is to be used to synthesize
8 mole of CO2, how many moles of oxygen are needed? How many
moles of octane?
|2.||Terephthalic acid, an important raw material for making Dacron, a synthetic fibre, is made from para-xylene by the following reaction.|
|C8H10 + 3 O2 ------------------>
C8H6O4 + 2 H2O
para- special conditions terephthalic
|How much terephthalic acid could be made from 154
grams of para-xylene in moles? In grams?
|3.||The chief process for converting iron ore, Fe2O3, into iron involves the combined action of coal and oxygen. Partial combustion of the carbon in coal give carbon monoxide.|
|2 C + O2 --------> 2 CO|
|In a series of steps, CO acts on Fe2O3, with the overall result|
|Fe2O3 + 3 CO -----------> 2 Fe + 3 CO2|
|(a) In an experiment done on a very small scale to test the efficiency of new approaches, a sample of 324 grams of Fe2O3 was converted into iron. How much iron, in theory, could form from this sample, in moles? In grams?|
|(b) The actual yield of iron in this test was 198
grams. What was the percentage yield?
|4.||Aluminum oxide, Al2O3, a
buffing powder, is to be made by combining 5.00 grams of aluminum with
oxygen, O2. How much oxygen is needed in moles? In grams?
|5.||Calculate how many grams of K2Cr2O7
are needed to make 35.8 grams of I2 according to the following
|K2Cr2O7 + 6 NaI
+ 7 H2SO4 ------> Cr2(SO4)3
+ 3 I2 + 7 H2O + 3 Na2SO4 +
|6.||The nitrite ion (NO2-) in
potassium nitrite is changed to the nitrate ion by the action of potassium
permanganate (KMnO4) in sulphuric acid solution.
|5 KNO2 + 2 KMnO4 + 3 H2SO4 ------> 5 KNO3 + 2 MnSO4 + K2SO4 + 3 H2O|
|How many moles and how many grams of KMnO4
are needed to carry out this reaction on 11.4 grams of KNO2?
|7.||If 2.56 grams of chlorine, Cl2, are
to be used to prepare dichlorine heptoxide, Cl2O7,
how many moles and how many grams of oxygen are needed?
|8.||Given that XeF6(l) + 3 H2O(l) ---------> XeO3(s) + 6 HF(g)|
|How many moles of:|
|a) water are needed to produce 1 mole of XeO3?|
|b) XeO3 does 59.8 grams represent?|
|c) water are needed to produce 59.8 grams of XeO3?
|9.||How many grams of CO2 gas are released when a 50.0 grams sample of Na2CO3 that is 60.0 percent pure reacts completely with excess HCl?|
|Na2CO3(aq) + 2 HCl(aq) ------------>
CO2(g) + H2O(l) + 2 NaCl(aq)
|10.||Calculate the number of moles of each of the ions in the following solutions.|
|(a) 25.0 mL of 1.30 M KOH|
|(b) 37.5 mL of 0.50 M CaCl2|
|(c) 20.0 mL of 0.50 M (NH4)2CO3|
|(d) 35.0 mL of 0.40 M Al2(SO4)3
|11.||Epsom salts is MgSO4.7H2O.
How many grams of this compound are needed to react completely 100.0 mL
of 0.100 M BaCl2 solution?
|12.||A mixture is prepared by adding 20.0 mL of 0.200 M Na3PO4 to 30.0 mL of 0.150 M Ca(NO3)2.|
|(a) What weight of Ca3(PO4)2 will be formed?|
|(b) What will be the concentrations of each of
the ions in the mixture after reaction?
|13.||How many millilitres of 0.500 M KOH are needed
to react completely with 60.0 mL of 0.250 M FeCl2 solution to
|14.||How many millilitres of 0.600 M HCl solution are
needed to supply 4.00 x 10-2 mol HCl?
|15.||A solution is labelled 0.230 M Fe2(SO4)3. How many moles of Fe3+ and SO42- are in 75.0 mL of this solution?|