1.What values of x,  y andz balance the equation:
xSO2    +   yH+  +   Cr2O72– → 3SO42–  + z Cr3++  H2O ?
2.What is the stoichiometric ratio of solid phosphorus (P) tochlorine gas (Cl2) required to give phosphorustrichloride (PCl3)?
3.What is the mass fraction of carbon in anilineC6H5NH2 expressed as apercentage?
4.
Arrange the following in order of increasing amount ofsubstance:
(i) Â Â Â Â Â Â Â Â Â Â 24 g of sodium metal
(ii) Â Â Â Â Â Â Â Â Â 40 g ofcarbon dioxide
(iii)Â Â Â Â Â Â Â Â Â 4 g ofhydrogen gas
5.What volume of 0.220 M NaOH(aq) should be used to prepare 303mL of 2.02 x 10–3 M NaOH(aq) ?
6.
Gold hydroxide Au(OH)3 is prepared for electroplatinggold by the following reaction
2 KAuCl4(aq) + 3 Na2CO3(aq) + 3H2O(l) → 2 Au(OH)3(s) + 6 NaCl(aq) + 2KCl(aq) + 3 CO2(g)
The following amounts are mixed KAuCl4 = 2.3 mol,Na2CO3 = 7.0 mol and H2O = 10L.
What is the limiting reagent, and what amount of gold hydroxide isformed if the reaction is ‘stoichiometric’? (M(H2O) = 18 g mol–1, Ï(H2O) = 1.0kg L–1)
Select one:
a. Na2CO3 , 1.57 mol
b. KAuCl4 , 4.6 mol
c. KAuCl4 , 2.3 mol
d. H2O , 6.9 mol
e. KAuCl4 , 6.9 mol
7.
What are the chemical formulae for the following acids: nitricacid, acetic acid, hydrochloric acid, sulfuric acid?
Select one:
a. H2NO3, CH3COOH,HClO2, H2SO3
b. HNO2, CH3COOH, HCl, HSO3
c. HNO3, CH3CH2OH, HCl,H2SO3
d. HNO2, CH3CH2OH, HClO,H2SO4
e. HNO3, CH3COOH, HCl, H2SO4