Chemistry Past Questions And Answers
Consider the reaction represented by the equation: 2SO2(g) + O2(g) ⇌ 2SO3(g); Δ H = - 197 kJ/mol Which of the following conditions will not increase the yield of sulphur (VI) oxide?
- A. Increase in temperature
- B. Decrease in temperature
- C. Increase in pressure
- D. Addition of O2 into the mixture
Consider the exothermic reaction 2SO2(g) + O2(g) (\rightarrow\)SO3(g). If the temperature of the reaction is reduced from 600°C to 300°C and no other changes take place then
- A) the reaction rate increases
- B) concentration of SO3 decreases
- C) concentration of SO3 ?increases
- D) SO2 gas becomes unreactive
The IUPAC name of the compound CF 3 CHBrCl is
- A) 2-chloro-2-bromo-1,1,1-trifluoroethane
- B) 2-bromo-2-chloro-1,1,1-trifluoroethane
- C) 1-bromo-1-chloro-2,2,2-trifluoroethane
- D) 1,1,1-trifluoro-2-bromo-2-chloroethane
A mixture of iodine and sulphur crystals can be separated by treatment with
- A) water to filter off sulphur
- B) carbon (IV) suiphide to filter off iodine
- C) ethanoic acid to filter off sulphur
- D) methanol to filter off iodine
The pollutants that are likely to be present in an industrial environment are
- A)H\(_2\)S, SO\(_2\) and oxides of nitrogen
- B)NH\(_3\), HCl and CO
- C)CO\(_2\), NH\(_3\), and H\(_2\)S
- D)dust, NO and Cl\(_2\) /
In a mixture of gases which do not react chemically together, the pressure of the individual gas is?
- A. atmospheric pressure
- B. vapor pressure
- C. total pressure
- D. partial pressure
For each oxygen atom in hydrogen peroxide which acts as an oxidant, there is an oxygen atom which acts as a/an
- A) Oxidant
- B) reductant
- C) oxidizing agent
- D) catalyst
Which of the following arrangements shows increasing order of reactivity of the halogens?
- A. F2 > Cl2 > Br2 >I2
- B. I2< Br2< Cl2
- C. F2< Cl2< Br2
- D. I2 > Br2 > Cl2 > F2
If 5.00cm3 of 0.20 mol dm-3Na2CO3 was diluted with distilled water to obtain 250 cm3 solution, what is the concentration of the resulting solution?
- A. 0.004 mol/dm3
- B. 0.02 mol/dm3
- C. 0.20mol/dm3
- D. 0.40mol/dm3
Elements which belong to the same group in the Periodic Table are characterized by
- A. difference of +1 in the oxidation numbers of successive members
- B. presence of the same number of outermost electrons in the respective atoms
- C. difference of 14 atomic mass units between successive members
- D. presence of the same number of electron shells in the respective atoms