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CBSE Questions for Class 11 Medical Chemistry Equilibrium Quiz 13 - MCQExams.com

When 0.1 mol arsenic acid, H2AsO4 is dissolved in 1L buffer solution of pH=4, which of the following hold good? K1=2.5×104,K2=5×104,K3=2×1023 for arsenic acid [<< sign denotes that the higher concentration is at least 100 times more than the lower one]. 
  • [H2AsO4]<<[H2AsO4]
  • [H2AsO4]<<[HAsO24]
  • [HAsO24]<<[HAsO4]
  • [AsO24]<<[HAsO24]
To prepare a buffer of pH 8.26 amount of (NH4)2SO4 to be added to 500 mL of 0.01 M NH4OH solution is: [pKa(NH+4)=9.26]
  • 0.05 mole
  • 0.025 mole
  • 0.10 mole
  • 0.005 mole
Percentage ionisation of water at certain temperature is 3.6×107%. Calculate Kw and pH of water.
  • 1014, pH=6/7
  • 4×1014, pH=6.7
  • 2×1014, pH=7
  • 1014, pH=7
1 litre buffer solution (HA+NaA)pH=4 , is mixed with  2 litre buffer solution (HA+NaA)pH=4.3. pH of resulting solution if both solutions are initially 0.1M MA.
[Given (Ka)HA=104;log2=0.3;log3=0.48;log5=0.7]
776050_c6405e8c959c4479a3e094a16699b945.png
  • 4.2
  • 4.22
  • 4.15
  • 6.4
What is the concentration of unionized acetic acid in the solution?
  • 0
  • 4.9×1010 M
  • 7×108 M
  • 2.45×1010 M
The relationship between the molar solubility(z) of MgF2 in 0.10 M Mg(NO3)2 and of Ksp of MgF2 is:
  • (Ksp/0.10)1/2
  • (Ksp/0.40)1/2
  • (Ksp/4)1/2
  • (Ksp)1/2
Which of the following mixtures will be a buffer solution when dissolved in 500.00 ml of water?
  • 0.200 mol of aniline and 0.200 mol of HCl
  • 0.200 mol of aniline and 0.400 mol of NaOH
  • 0.200 mol of NaCl and 0.100 mol of HCl
  • 0.200 mol of aniline and 0.100 mol of HCl
An aqueous solution contains 0.01 M \ RNH_2​ (K_b​=2×10^{−6}) and 10^{−4} M\  NaOH.The concentration of OH^− is nearly:
  • 2.414\times 10^ {-4}M
  • 10^ {-4}M
  • 1.41\times 10^ {-4}M
  • 2\times 10^ {-4}M
One litre of water contains 1.0\times { 10 }^{ -7 } moles of { H }^{ + } ions. The degree of ionization of water is:
  • 1.8\times { 10 }^{ -9}%
  • 0.8\times { 10 }^{ -9 }%
  • 3.6\times { 10 }^{ -9 }%
  • 3.6\times { 10 }^{ -7 }%
Solid Ba{({NO}_{3})}_{2} is gradually dissoved in a 1\times {10}^{-4}M {Na}_{2}{CO}_{3} solution. At what minimum conc. of {Ba}^{-2} will a precipitate of Ba{CO}_{3} begin to form? ({K}_{sp} for Ba{CO}_{3}=5.1\times {10}^{-9})
  • 4.1\times {10}^{-5}M
  • 8.1\times {10}^{-7}M
  • 5.1\times {10}^{-5}M
  • 8.1\times {10}^{-8}M
Which of the following is a true statement:
  • The ionisation constant and ionic product of water are same.
  • Water is a strong electrolyte.
  • The value of ionic product of water is less than that of its ionisation constant
  • At 298\ K, the number of { H }^{ + } ions in a litre of water is 6.023\times { 10 }^{ 16 }.
The ionization constant of benzoic acid is 6.46 \times 10^{-5} and K_{sp} for silver benzoate is 2.5\times 10^{-13}. How many times is silver benzoate more soluble in a buffer of pH = 3.19 compared to its solubility in pure water?
  • 4
  • 3.32
  • 3.01
  • 2.5
A sodium salt on treatment with {MgCl}_{2} gives white precipitate only on heating. The anion of the sodium salt is:
  • { HCO }_{ 3 }^{ - }
  • { CO }_{ 3 }^{ 2- }
  • { NO }_{ 3 }^{ - }
  • { SO}_{ 4 }^{ 2- }

If the ionic product of water varies with temperature as follows and the density of water is nearly constant for this range of temperature. The given equilibrium process is:
{ H }^{ + }+OH\rightleftharpoons { H }_{ 2 }O

872921_f390b624b0d14407acdab6b187e00576.png
  • Exothermic
  • Endothermic
  • Cant say
  • Ionization
The K_{sp} of Ag_{2}CrO_{4}, AgCl, AgBr and AgI are respectively, 1.1\times 10^{-12}, 1.8\times 10^{-10}, 5.0\times 10^{-13} and 8.3\times 10^{-17}. Which of the following salts will precipitate last if AgNO_{3} solution is added to the solution containing equal moles of NaCl, NaBr, NaI and Na_{2}CrO_{4}?
  • Ag_{2}CrO_{4}
  • AgI
  • AgCl
  • AgBr
Which of the following statements is true?
  • {H}_{3}{PO}_{3} is stronger acid than {H}_{2}{SO}_{3}
  • In aqueous medium HF is a stronger acid than HCl
  • HCl{O}_{4} is a weaker acid than HCl{O}_{3}
  • H{NO}_{3} is a stronger acid than H{NO}_{2}
If S_0, S_1, S_2 and S_3 are the solubilities in water of AgCl, 0.01 \,M \,CaCl_2, 0.01 \,M \,NaCl and 0.5 \,M \,AgNO_3 solutions, respectively, then which of the following is true?
  • S_0 > S_2 > S_1 > S_3
  • S_0 = S_2 = S_1 > S_3
  • S_3 > S_1 > S_2 > S_0
  • none of these
As_2S_3 solution has negative charge, capacity to precipitate is highest in:
  • AlCl_3
  • Na_3PO_4
  • CaCl_2
  • K_2SO_4
The number of { H }_{ 3 }{ O }^{ + } ions present in 10 ml of water at { 25 }^{ 0 }C is 
  • 6.023\times { 10 }^{ -14 }
  • 6.023\times { 10 }^{ 14 }
  • 6.023\times { 10 }^{ -19 }
  • 6.023\times { 10 }^{ 19 }
The amount { CH }_{ 3 }{ NH }_{ 2 } dissolved in 2\ L of water that it produces concentration { OH }^{ - } equal to 5\times { 10 }^{ -4 }\ M, is 
[Given { K }_{ b } of { CH }_{ 3 }{ NH }_{ 2 }=2\times { 10 }^{ -6 }]
  • 5.6\ gm
  • 3.88\ gm
  • 7.75\ gm
  • 8.3\ gm
On adding ammonia to water,
  • ionic product will increase
  • ionic product will decrease
  • [H_{3}O^{+}] will increase
  • [H_{3}O^{+}] will decrease
With increase in temperature, ionic production of water 
  • decreases
  • increases
  • remains same
  • may increases or decreases
 Which buffer solution has maximum pH? 
  • mixture which is 0.1 M in \mathrm { CH } _ { 3 } \mathrm { COOH } and 0.1 M in \mathrm { CH } _ { 3 } \mathrm { COONa } \left[ \mathrm { pK } _ { \mathrm { a } } \left( \mathrm { CH } _ { 3 } \mathrm { COOH } \right) = 4.74 \right]
  • mixture which is 0.2 M \mathrm { CH } _ { 3 } \mathrm { COOH } and 0.2 M in \mathrm { CH } _ { 3 } \mathrm { COONa }
  • mixture which is 0.1 M in \mathrm { NH } _ { 4 } \mathrm { Cl } and 0.1 M in \mathrm { NH } _ { 4 } \mathrm { OH } \left[ \mathrm { pK } _ { \mathrm { a } } \left( \mathrm { NH } _ { 4 } ^ { + } \right) = 9.26 \right]
  • all the solution have equal pH which is 4.74
At certain temperature { K }_{ w } for water 4\times { 10 }^{ -14 }. Which of the following is incorrect for impure water at given temperature?
[Given: log\ 2 = 0.3]
  • pH=6.7 and water is acidic.
  • pH=6.7 and water is neutral.
  • pOH=6.7 and water is neutral.
  • pH + pOH = 13.4
How many grams of NaOH is to be added to one litre of 1 M H_2CO_3 to get a HCO^{-}_3/ CO^{-2}_3 buffer of maximum capacity ?
  • 90 gm
  • 60 gm
  • 20 gm
  • 50 gm
Solubility of silver cyanide is maximum in
  • Acidic buffer solution
  • Basic buffer solution
  • In pure water
  • Equal in all
A sample of water containing some dissolved table sugar and common salt is passed through organic ion exchange resins. The resulting water will be
  • Sweet
  • Salty
  • Tasteless
  • None of these
At 100^\circ C, value of K_{w} is 
  • 1.0\times 10^{-14}\quad m^{2}
  • less than 1.0\times 10^{-14}\quad m^{2}
  • greater than 1.0\times 10^{-14}\quad m^{2}
  • Zero
Calculate the degree of ionization of 0.04M HOCl solution having ionization constant 1.25\times { 10 }^{ -4 }?
  • 0.025
  • 0.25
  • 0.5
  • 0.055
When a solution of silver nitrate is added to pure carbon tetrachloride :
  • A light blue precipitate soluble in ammonia is obtained
  • A curdy precipitate insoluble in ammonia is obtained
  • A Pale yellow precipitate in ammonia is formed
  • No precipitate is formed
Which of the following compound has the maximum degree of ionization?
  • 1 M NH_3
  • 0.001 M  NH_3
  • 0.1 M NH_3
  • 0.0001 M NH_3
In which of the following , the solubility of AgCl will be minimum ?
  • 0.01 \ M \ Na_2{ SO_4}
  • Pure water
  • 0.01 \ M \ CaCl_2
  • 0.01 \ M\  NaCl
Which shows weak ionisation in water?
  • H_2SO_4
  • NaCl
  • HNO_3
  • NH_3
The percentage of pyridine \left( {{C_5}{H_5}N} \right) that forms pyridinum ion \left( {{C_5}{H_5}{N^ + }H} \right) in a 0.10M aqueous pyridine solution \left( Given - {{K_b}, for \  {C_5}{H_5}N = 1.7 \times {{10}^{ - 9}}} \right) is? 
  • 0.0060\%
  • 0.013\%
  • 0.77\%
  • 1.6\%
At any temperature, the proton concentration of water is 
  • {10}^{-7}M
  • < {10}^{-7}M
  • > {10}^{-7}M
  • \sqrt { { K }_{ w } }
Amongst the following hydroxides,the one which has the lowest value of{ K }_{ SP } is?
  • { Mg(OH) }_{ 2 }\quad \quad \quad
  • Ca(OH)_{ 2 }
  • Ba(OH)_{ 2 }
  • Be(OH)_{ 2 }
Degree of dissociation of 0.1 M HCN solution is 0.01%. Its ionisation constant would be 
  • 10^{-3}
  • 10^{-5}
  • 10^{-7}
  • 10^{-9}
If the ionic product of water is   1.96 \times 10 ^ { - 14 }  at  35 ^ { \circ } \mathrm { C } .  What is its value at  10 ^ { \circ } \mathrm { C }
  • 2.95 \times 10 ^ { - 14 }
  • 1.96 \times 10 ^ { - 7 }
  • 2.95 \times 10 ^ { - 15 }
  • 3.9 \times 10 ^ { - 12 }
Which of the following solution mixture will show resistance to the small addition of acids?
  • 500ml\ of\ 0.1N\ CH_{3}COOH+500ml\ of\ 0.1N\ NaOH
  • 500ml\ of\ 0.1N\ CH_{3}COOH+500ml\ of\ 0.1N\ HCl
  • 500ml\ of\ 0.1N\ CH_{3}COOH+500ml\ of\ 0.2N\ NaOH
  • 500ml\ of\ 0.2N\ CH_{3}COOH+500ml\ of\ 0.1N\ NaOH
Which of the following salt solution will act as a buffer?
  • C{H_3}COON{H_4}\left( {aq.} \right)
  • N{H_4}Cl\left( {aq.} \right)
  • C{H_3}COONa\left( {aq.} \right)
  • NaCl\left( {aq.} \right)
\frac { N } { 10 } acetic acid was titrated with \frac { N } { 10 } NaOH.When 25 \% , 50 \% and 75\% of titration is over then the pH of the solution will be : \left[ \mathrm { K } _ { a } = 10 ^ { - 5 } \right]
  • 5 + \log 1 / 3,5,5 + \log 3
  • 5 + \log 3,4,5 + \log 1 / 3
  • 5 - \log 1 / 3,5,5 - \log 3
  • 5 - \log 1 / 3,4,5 + \log 1 / 3
In decimolar solution, CH_{3}COOH is ionised to the extent of 1.3 %. If log 1.3 = 0.11, what is the pH value of the solution?
  • 3.89
  • 4.89
  • 2.89
  • Unpredictable
On addition of sodium acetate, the ionization of acetic acid:
  • cannot be predicted
  • decreases
  • increases
  • remains unaffected
The concentration of hydronium (H_{3}O^+) ion in water is
  • Zero
  • 1\times 10^{-14}gm\ ion/litre
  • 1\times 10^{7}gm\ ion/litre
  • 1\times 10^{-7}gm\ ion/litre
Which may be added to one litre water to act as a buffer.
  • 1 mole of HC_{2}H_{3}O_{2} and 1 mole of Hcl
  • 1 mole of NH_{4}OH and 0.5 mole of NaOH
  • 1 mole of NH_{4}Cl and 1 mole of Hcl
  • 1 mole of HC_{2}H_{3}O_{2} and 0.5 mole of NaOH
At certain temperature, the { H }^{ + } ion concentration of water is 4\times { 10 }^{ -7 }M then the value of { K }_{ w } at the same temperature is 
  • { 10 }^{ -14 }{ M }^{ 2 }
  • 4\times { 10 }^{ -14 }{ M }^{ 2 }
  • 1.6\times { 10 }^{ -13 }{ M }^{ 2 }
  • 4\times { 10 }^{ -7 }{ M }^{ 2 }
The mass in grams of potassium permanganate (MM = 158) crystals required to oxidize 750\,\,c{m^3} of 0.1 M Mohr's salt solution in acidic medium is about?
  • 11.8
  • 5.8
  • 6.0
  • 2.4
Degree of hydrolysis for a salt of weak acid and strong base can be changed by 
  • Increasing concentration of salt
  • Increasing temperature
  • Adding base
  • All of these
Which of the following mixture can form buffer solution ?
  • C{H_3}COOH + C{H_3}COONa
  • NaCl + NaOH
  • HCl + N{H_4}Cl
  • C{H_3}COOH + HCl
If pH of a saturated solution of Mg(OH)_2 is 12.
Find its K_{sp}
  • 2\times 10^{-4}
  • 5\times 10^{-5}
  • 4\times 10^{-6}
  • 5\times 10^{-7}
0:0:2


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