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Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

If a steam-jacket eudiometer with 23ml of oxygen and 4ml of hydrogen are mixed over mercury, determine the total volume in ml of the gas after the mixture was sparked?

  1. $16$
  2. $25$
  3. $34$
  4. $36$
  5. $40$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$\displaystyle  2H _2 + O _2 \rightarrow 2H _2O$
2 moles of hydrogen will react with 1 mole of oxygen to form 2 moles of water.
Volume is directly proportional to the number of moles.
4 ml of hydrogen will react with $\displaystyle  \dfrac {4 \times 1}{2}= 2$  ml of oxygen to form 4 ml of water.
$\displaystyle  23-2 = 21 ml$  of oxygen will be left uncombined.
Thus, after the mixture was sparked, 21 ml oxygen and 4 ml water are present.
Total volume of the gas after the mixture was sparked $\displaystyle  = 21 + 4 = 25 $ ml.

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

_______is a technology used to produce enriched uranium by forcing gaseous uranium hexafluoride through semipermeable membranes.

  1. Gas solubility

  2. Gas condensation

  3. Solidification

  4. Gas diffusion
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Gaseous diffusion is a technology used to produce enriched uranium by forcing gaseous uranium hexafluoride through semipermeable membranes. This produces a slight separation between the molecules containing uranium-235 and uranium-238. By use of a large cascade of many stages, high separations can be achieved. 

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

A technique in which two liquids are separated by heating process is known as :

  1. distillation

  2. filtration

  3. evaporation

  4. sublimation
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Distillation is a process of separating the component or substances from a liquid mixture by selective evaporation and condensation. Distillation may result in essentially complete separation (nearly pure components), or it may be a partial separation that increases the concentration of selected components of the mixture.

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

A cheque was suspected to be forged. Which technique could be used to compare the various pigments in the different inks?

  1. Chromatography

  2. Evaporation

  3. Crystallisation

  4. Sublimation
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A cheque was suspected to be forged. Chromatography could be used to compare the various pigments in the different inks.  Here, different inks will have different affinity for  stationary phase  and solvent (mobile phase).

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

Fractional distillation is used to obtain the components of which of the following?
I air
II seawater
III muddy water
IV crude oil 

  1. I, II

  2. II, III

  3. I, IV

  4. I, III
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Fraction distillation is based upon the separation of components having very less boiling point difference, therefore components of crude oil and air can be separated using fractional distillation. In the air and in crude oil, the difference in boiling point of different components is very less. 

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

The vapour pressure of pure $A$ is $10$ torr and at the same temperature when $1\ g$ of $B$ is dissolved in $20\ g$ of $A$, its vapour pressure is reduced to $9.0$ torr. If the molecular mass of $A$ is $200\ amu$, then the molecular mass of $B$ is:

  1. $100\ amu$
  2. $90\ amu$
  3. $75\ amu$
  4. $120\ amu$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

So $0.1=\dfrac{moles \,\, of \,\, B}{moles of A+B}$

$0.1=\dfrac{1/m^2}{\dfrac{1}{m _2}+\dfrac{20}{200}}$
$0.1=\dfrac{1/m _2}{\dfrac{1}{m _2}+0.1}$
$\dfrac{0.1}{m _2}+0.01=\dfrac{1}{m _2}-\dfrac{0.1}{m _2}$
$0.01=\dfrac{0.9}{m _2}$
$m _2=\dfrac{0.9}{0.01}=90amu$

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

Which of the following technique is used for the separation of a mixture of a liquid and a gas?

  1. Boiling

  2. Sublimation

  3. Crystallization

  4. Fractional distillation
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The technique used for the separation of a mixture of a liquid and a gas is boiling. The gas is removed by application of heat.  With the increase in temperature, the solubility of gas decreases. The gas is collected separately

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

A mixture of hydrogen and chlorine can be seperated by passage through a porous pot.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A mixture of hydrogen and chlorine can be separated by passage through a porous pot. This is because the diffusion of hydrogen more than that of chlorine in the porous pot. So, most of chlorine remains outside the pot.

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

${K} _{H}$ values for ${Ar} _{(g)}, {CO} _{2(g)}, {HCHO} _{(g)}$ and ${CH} _{4(g)}$ are $40.39,1.67,1.83\times {10}^{-5}$ and $0.413$ respectively. Arrange these gases in the order of their increasing solubility ?

  1. $HCHO< {CH} _{4}< {CO} _{2}< Ar$
  2. $HCHO< {CO} _{2}< {CH} _{4}< Ar$
  3. $Ar< {CO} _{2}< {CH} _{4}< HCHO$
  4. $Ar< {CH} _{4}< {CO} _{2}< HCHO$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The solubility of the gas is inversely proportiona to the $K _H$ value. Here, $Ar$ gas has the highest $K _H$ value so least solubility and $HCHO$ gas has the least $K _H$ value so highest solubility.


So, the correct option is C.

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

Alcohol and water are best separated from one another by :

  1. distillation

  2. crystallization

  3. manual separation

  4. chromatography

  5. filtration
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Alcohol and water are best separated from one another by distillation. 


Alcohol and water are miscible but they have different boiling points.

If the difference in the boiling points of alcohol and water is less, fractional distillation can be used.

Hence the correct option is A.