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CBSE Questions for Class 11 Medical Chemistry Some Basic Concepts Of Chemistry Quiz 14 - MCQExams.com

60g of solution containing 40% by mass of NaCl are mixed with 100g of a solution containing 15% by mass NaCl. Determine the mass percent of sodium chloride in the final solution.
  • 24.4%
  • 78%
  • 48.8%
  • 19.68%
An organic compound contains 69% carbon and 4.8% hydrogen, the remainder being oxygen. What will be the masses of the carbon dioxide and water produces when 0.20g of this substance is subjected to the complete combustion?
  • 0.69 g and 0.048g
  • 0.506 g and 0.086g
  • 0.345 g and 0.0024 g
  • 0.91 g and 0.72 g
If a solution contains 34.2 g of sugar in 100 g of water. Find the concentration inn terms of mass by mass percentage of the solution?
  • 20 %
  • 25.48 %
  • 50 %
  • 10 %
A mixture of NaHCO3  and Na2CO3 weighs 950 gm. When the mixture is heated strongly in an open vessel, till constant weight, the mass of sample reduced by 155 gm. The correct information(s) is/ are ?
  • The mass percent of NaHCO3 in initial mixture = 50%
  • The mole percent of Na2CO3 in initial mixture = 50%
  • Final sample contains only Na2O
  • The loss in mass is only due to CO2 gas evolved
P and Q are two elements which form P2Q3 and PQ2. If 0.15 mole of P2Q3 weight 15.9 g and 0.15mole of PQ2 weight 9.3 g. what are atomic weights of P and Q respectively?
  • 18 and 26 
  • 26 and 26
  • 26 and 18
  • 18 and 18
What percent of a sample of nitrogen must be allowed to escape if its temperature, pressure, and volume are to be changed from 220oC, 3atm and 1.65litre to 110oC, 0.7 atm and 1.00 litre respectively?
  • 81.8%
  • 71.8%
  • 76.8%
  • 86.8%
3g of activated charcoal was added to 50mL of acetic acid solution (0.06N) in a flask. After an hour it was filtered and the strength of the filtrate was found to be 0.042N. The amount of acetic acid absorbed (per gram of charcoal) is ?
  • 18mg
  • 36mg
  • 42mg
  • 54mg
A substance contains 3.4%S. if it contain two atom of sulphur per molecule then minimum molecular weight of substance will be:
  • 188.2
  • 94.1
  • 1882
  • 282.3
Find out the weight of solute (M. wt. 60) that is required to dissolve in 180g water to reduce the vapour pressure to 45th of pure water:
  • 120g
  • 150g
  • 300g
  • 75g
A sample of diesel has the same knocking characteristics as a 60 ml mixture of cetane and a- methyl  naphthalene mixed in 2 :1 ratio .The cetane number of the diesel sample is :
  • 60
  • 40
  • 66.6
  • 33.3
4.24 g of an organic compound on combustion produces 8.45 g of CO2 and 3.46 g of water. The mass percentage of C and H in the compound respectively are:
  • 27.2,18.2
  • 54.4,9.1
  • 9.1,54.4
  • 18.2,27.2
Air has three major components : nitrogen,oxygen  and argon. Given that one mole of air at sea level is made up of 78% nitrogen, 21% oxygen, and 1% argon, by volume. What is the density of air? Assume that gases behave in an ideal manner. (Atomic mass of argon is 40 amu)
  • 14.62 g/L
  • 1.3 g/L
  • 29 g/L
  • 0.65 g/L
The volume of 0.1 M H2SO4 required to neutralize 30 mL of 2.0 M NaOH is:
  • 100 mL
  • 300 mL
  • 400 mL
  • 200 mL
When 15gm of a mixture of NaCl and Na2CO3 is heated with dilute hydrochloric acid, 2.5gm of CO2 is evolved at NTP. Calculate percentage composition of Na2CO3 in a mixture.
  • 59.85%
  • 40.15%
  • 30%
  • 70%
A mixture of C2H2 AND  C3H8 occupied a certain volume at 80 mm Hg . The mixture wsa completely burnt to CO2 and H2O (l). When the pressure of CO2 was found to be 230 mm Hg at the same temperature and volume, the mole fraction of C3H8  in the mixture is 
  • 0.125
  • 0.875
  • 0.6
  • 0.8
NA4 atoms of an element ionise by absorbing X kJ of energy, then the ionisation energy of the elements is: (NA= Avogadro number)
  • 2X
  • 4X
  • 4X
  • 14X
Two oxide of metal contain 27.6% and 30% oxygen respectively. If the formula of first oxide is M3O4 then formula of second oxide is -
  • MO
  • M2O
  • M2O3
  • MO2
81gm mixture of MgCO3(s) NH2COONH4(s) in equimolar ratio is heated in open to constant mass. If vapour density of gaseous mixture evolved was found to be 614, then find the mole % of MgCO3 in original sample.

Given that: MgCO3(s)ΔMgO(s)+CO2(g) 

H2COONH4(s)Δ2NH3(g)+CO2(g)N
  • 50%
  • 51.9%
  • 70.9%
  • 59.1%
In the mixture of (NaHCO3+Na2CO3) in 1:1 molar ratio, the volume of HCl required is x ml with methyl orange and y ml with phenolphthalein indicator for 2 different titrations from start for equal volumes of original solution. The relation between x and y is:
  • x=3y
  • y=3x
  • x=6y
  • y=6x
Substance
Boiling point (0C)
Melting point (0C)
A-183-219
B445119
C78-15

Point out the physical states of A, B, and C at room temperature (300C).
  • Gas, solid, liquid
  • Gas, liquid, solid
  • Liquid, solid, gas
  • Solid, liquid, gas
100 gm impure CaCO3 on heating gives 5.6 lit. CO2 gas at NTP. Find the percentage of calcium in CaCO3 sample.
  • 1
  • 40
  • 10
  • 30
If a sample of MgBr2 contains 4×1020Br ions, then the number of Mg2+ ions present in it is:
  • 4×1020
  • 8×1020
  • 2×1020
  • 1×1020
Vapour density of the equilibrium mixture of NO2 and N2O4 is found to be 40 for the equilibrium. Calculate percentage of NO2 in the mixture:  N2O4
  • 10 %
  • 5 %
  • 26.08 %
  • None of these
0.1 g of a solution containing Na_2CO_3 and NaHCO_3 requires 10 mL of 0.01 N HCl for neutralization using phenolphthalein as an indicator. Wt % of Na_2CO_3 in the mixture is 
  • 25
  • 32
  • 50
  • 10.6
12\ g of impure cyanogen undergoes hydrolysis by two different pathways :
i) (CN)_{2}+4H_{2}O \rightarrow (NH_{4})_{2} C_{2}O_{4}
ii) (CN)_{2}+2H_{2}O \rightarrow NH_{2}CONH_{2}
The same amount of urea was obtained when 11.52\ g of pure ammonium carbonate was heated. If 20\ mL of 1.6\ M acidic KMnO_{4} was required to completely oxidise (NH_{4})_{2}C_{2}O_{4} then which of the following statement is incorrect ?
  • \% purity of cyanogen is 86.67\%.
  • \% purity of cyanogen is 60.67\%.
  • \% progress in case (i) is 40\%.
  • \% progress in case (ii) is 60\%.
0.1 g of a solution containing { Na }_{ 2 } { Co }_{ 3 } and { NaHCO }_{ 3 } requires 10 mL of 0.01 N HCl for neutralization using phenolphthalein as an indicator.Wt.% of  { Na }_{ 2 } { Co }_{ 3 } in the mixture is
  • 25
  • 32
  • 50
  • 10.6
What weight of NaHSO_3 is required to react with 100mL of solution containing 0.33g of NaIO_3 according to the following reaction 
{IO}_{3}^{\Theta}+HS{O}_{3}^{\Theta}\longrightarrow I^{\Theta}+{SO}_{4}^{2-}
  • 0.52g
  • 5.2g
  • 1.04g
  • 10.4g
Avogadro number is the number of molecule present in
  • 1 lit of any gas at NTP
  • 10 lit of any gas at NTP
  • 11.2 lit of any gas at NTP
  • 22.4 lit of any gas at NTP
A gas cylinder of the capacity of 20 dm^{3} is filled with gas X, the mass of which is 10\ gm. When the same cylinder is filled with hydrogen gas at the same temperature and pressure the mass of the hydrogen is 2 \ gm hence the relative molecular mass of the gas is:
  • 5
  • 10
  • 15
  • 20
The O^{18}/O^{16} ratio in some meteorites is greater than the used to calculate the average atomic mass of oxygen one earth. The average mass of an atom of oxygen in these meteorites is ______ that of terrestrial oxygen atom?
  • equal to
  • greater than
  • less than
  • none of these
An oxide, X_{2}O_{3} is oxidized to X_{4}^{-} by Cr_{2}O_{7}^{2-} in acid medium. The number of moles of X_{2}O_{3} oxidized per mole of Cr_{2}O_{7}^{2-} is
  • 2
  • 3
  • 3/2
  • 2/3
Gold crystallizes with FCC lattice for which the side length of the unit cell is 5.0\mathring { A } . If the density of gold is 10.5g/{cm}^{3}, the value of Avagadro number is (Au=198)
  • 6.022\times { 10 }^{ 23 }
  • 6.034\times { 10 }^{ 23 }
  • 5.966\times { 10 }^{ 23 }
  • 6.022\times { 10 }^{ 22 }
What percentage of hydrogen fluoride molecules is dimerized?
  • 50
  • 58.8
  • 76.47
  • 17.65
If the ratio of mole fraction of solute and solvent is unity, then the mass per cent of solute is (Molar masses of solute and solvent are X and Y respectively)
  • 50\%
  • \dfrac{X}{X+Y}\times 100\%
  • \dfrac{X}{Y}\times mass per cent of solvent
  • \dfrac{Y}{X}\times mass per cent of solvent
If in esterification, initially equal moles of alcohol and acid are taken. At equilibrium, unreacted alcohol and acid, on the treatment of sodium, produced H_2 which occupied 44.8 L at 0^o C and 1 atm. The percentage esterification of acid and alcohol is:
  • 25 %
  • 33.3 %
  • 50 %
  • 66.7 %
A solution containing 4.2 g of KOH and Ca(OH)_2 is neutralised by an acid. If it consumes 0.1 equivalent of acid, composition of sample in solution is which of the following?
  • 45%, 55%
  • 35%, 65%
  • 25%, 75%
  • 15%, 85%
Complete combustion of 858.0 \,g of compound X gives 63.2 \,g of CO_{2} and 1.28 \,g of H_{2}O. The lowest molecular mass X can have:
  • 43 \,g`
  • 86 \,g
  • 129 \,g
  • 172 \,g
The correct sequence in decreasing order of the percentage of nitrogen in the given compounds is
  • Urea > Ammonium chloride > Ammonium nitrate > Ammonium nitrite
  • Urea > Ammonium nitrate > Ammonium nitrite > Ammonium chloride
  • Urea > Ammonium nitrite > Ammonium Nitrate > Ammonium chloride
  • Urea > Ammonium nitrite > Ammonium chloride > Ammonium nitrate
Chemistry plays an important role in national economy.
  • True
  • False
0:0:4


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