Chemistry Chapter 6 Entry Test MCQs
101. In a reversible chemical reaction near to achieving equilibrium what would be the effect of doubling the concentration of reactants on equilibrium constant:
a. Become one –fourth
b. Also be doubled
c. Remain the same
d. Be halved
102. The mathematical relationship between buffer and its pH is given by:
a. Henderson
b. Haber
c. Born-Haber
d. Le-chatelier
103. In a reversible reaction, the color of a yellow reaction mixture becomes increasingly red with the passage of time until the equilibrium is attained. What will be the effect of addition of product to this solution?
a. Decrease in concentration of reactant
b. Darkening of red color
c. Decolourization
d. Yellowing of solution
104. For a gas phase endothermic reaction which proceeds with decrease in number of moles, the amount of product obtained depends upon:
a. P
b. T
c. T,P and Catalyst
d. T,P
105. KNO3 ⇌ K+ + NO3-1, if the process takes place with absorption of energy, an increase in temperature will:
a. Increase [KNO3]
b. Produce more ions
c. shift equilibrium backwards
d. Cause precipitation
106. BiCl3 + H2O ⇌ BiOCl + 2HCl. Which action will not make solution cloudy?
a. HCl addition
b. BiCl3 addition
c. BiOCl removal
d. H2O addition
107. Numerical value of KC is independent of all of these except:
a. ΔV
b. ΔC
c. ΔT
d. ΔP
108. optimum conditions of temperature and pressure to get maximum NH3 from N2 and H2 gasses is
a. 400oC and 200 – 300 atmosphere
b. 200oC and 10 atmosphere
c. 200oC and 100 atmosphere
d. 0oC and 1 atmosphere
109. Dissociation of H2S in water into ions is suppressed by addition of HCl because:
a. HCl reacts chemically with H2S
b. H2S is weak acid than HCl
c. H2S is strong acid than HCl
d. None of these
Dissociation Equilibrium constants
110. The concentration of sodium hydroxide is 10–4 moles per dm3. The PH of the solution will be:
a. 08
b. 11
c. 10
d. 4
111. pH of an aqueous solution is 10.0 Its pOH is:
a. 9
b. 7
c. 10
d. 4
112. Mark the correct statement:
a. Greater is pH value, stronger is the acid
b. Greater is the Ka value, stronger is the acid
c. Smaller is H+ ion concentration, stronger is acid
d. Greater is pKa value, stronger is the acid
113. According to Lewis theory:
- Acid is electron pair acceptor
- Base is electron pair donor
All of the following are Lewis acids EXCEPT:
a. AlCl3
b. H+
c. PCl3
d. BF3
114. Which of the following halide ions is stronger Lewis base?
a. Cl–
b. F–
c. I–
d. Br –
115. The pH of a solution is 5. To this solution sufficient acid was added and is pH decreases to 2. The increase in hydrogen ions concentration is:
a. 3 times
b. 100 times
c. 10 times
d. 1000 times
116. The pKb value for aqueous ammonia at 25°C is 4.8. What is the correct pKa value for the ammonium ions at this temperature?
a. 4.8
b. -4.8
c. 9.2
d. 2.2
117. The substance which has highest pH:
a. Milk of magnesia
b. Gastric juice
c. Vinegar
d. Soft drinks
118. One dm3 of water contains 10-7 moles of H+ ions. Percentage ionization of water is
a. 3.6 x 10-7
b. 1.8 x 10-7
c. 6.022 x 1023
d. 1 x 10-6
119. The solution in which H+ ion concentration is 1/100, its pOH is
a. 10
b. 13
c. 12
d. 2
120. The concentration of OH– of a solution having pH = 8 will be:
a. 1.0 x 10–7
b. 1.0 x 10–6
c. 1.0 x 10–8
d. 1.0 x 10–5
121. Which of the following is the strongest acid?
a. HNO3
b. HI
c. H2SO4
d. HClO3
122. Which one of the following groups of elements forms strongest bases?
a. IIIA
b. IVA
c. IA
d. IIA
123. Which one of the following statements is incorrect?
a. Strong acid has greater conc. of hydrogen ions
b. Strong acid has low pH value
c. Smaller is conc. of OH– ions weaker is the base
d. Greater is pKa value, stronger is the acid
124. When temperature is increased from 00C to 1000C, the value of Kw will:
a. Increases 75 times
b. Increases 10 times
c. Decreases 75 times
d. Decreases 2 times
125. 0.1M HCl solution has pH = 1.0. It is about hundred times stronger than acetic acid. Then the pH of acetic acid will b
a. 1.0
b. 0.1
c. 3.0
d. 2.0