Tag: heterogenous mixture - colloidal solution and its properties

Questions Related to heterogenous mixture - colloidal solution and its properties

Which of the following will form negatively charged colloidal solution?

  1. $100$ ml $0.1$M $AgNO _3+100$ ml $0.1$ M KI

  2. $100$ ml $0.2$M $AgNO _3+100$ ml $0.1$M KI

  3. $100$ml $0.1$M $AgNO _3+100$ ml $0.2$ M KI

  4. $100$ ml $0.2$M $AgNO _3+200$ ml $0.1$M KI


Correct Option: C
Explanation:

milli moles of $AgNO _3=100\times0.1=10$

milli moles of $KI=100\times.02=20$

$KI$ is in excess.

$AgI$ will be precipitated and excess $KI$ as $I^-$ ions will surround $AgI$ and form negative charged colloid.


Therefore, correct option is C.

Which of the following statement are false regarding colloidal solution?

P. Colloidal solutions are homogeneous in nature.

Q. Colloidal particles pass through an ordinary filter paper.

R. Colloidal particles can be seen with naked eyes.

S. Colloidal particles do not settle under gravity.
  1. P and R

  2. P and S

  3. Q and R

  4. R and S


Correct Option: A
Explanation:

Colloids are relatively stable in nature. The particles of the dispersed phase are in a state of continuous motion and remain suspended in the solution. 
Colloids require specialized filters known as ultrafilters for filtration.
Colloidal solutions are heterogeneous in nature.
Colloidal particles do not settle under gravity and they can't be seen with naked eyes.


Hence, option A selects the false statements about colloids.

The nature of colloidal solution obtained when excess $Fe{ Cl } _{ 3 }$ is added in precipitate of $Fe{ \left( OH \right)  } _{ 3 }$?

  1. positively charged

  2. negatively charged

  3. no charge

  4. All of the above


Correct Option: A
Explanation:
Peptization takes place forming a positively charged colloidal sol of $Fe(OH) _3$
Peptization is a process of passing of a precipitate into colloidal particles on adding suitable electrolyte. The electrolyte added is known as peptizing agent. A few examples of sols obtained by peptization are given below:
A reddish brown colored colloidal solution is obtained by adding small quantity of ferric chloride solution to the freshly precipitated ferric hydroxide.

Colloidal particles of soap sol in water is:

  1. Negatively charged

  2. Neutral

  3. Positively charged

  4. Unpredictable


Correct Option: A

Which of the following is positively charged colloidal particle?

  1. $Ag$

  2. $ { Al } _ { 2 } { O } _ { 3 }. { H } _ { 2 } \ { O }$

  3. $Au$

  4. $Pt$


Correct Option: B
Explanation:

Arsenic trisulphide $Au, Ag, Cu, Pt$ are negatively charged colloid as in upper carius arm experiment it will move towards the positive charge.

While metallic oxides $Al _2O _3\cdot xH _2O$ is a positively charged solution.

Which reaction gives colloidal solution

  1. $2Cu+{Cl} _{2}\rightarrow {Cu} _{2}{Cl} _{2}$

  2. $2H{NO} _{3}+3{H} _{2}S\rightarrow 3S+4{H} _{2}O+2NO$

  3. $2Mg+{CO} _{2}\rightarrow 2MgO+C$

  4. $2Cu+{O} _{2}\rightarrow 2CuO$


Correct Option: B

Which of the statement is correct? 

  1. Brownian motion of colloidal particles does not depend on the size of particles

  2. Adsorption is endothermic process

  3. Colloidal medicines are better because of their small surface area.

  4. Electrophoresis can be used for ppt of lyophibic colloid


Correct Option: D
Explanation:
Solution:- (D) Electrophoresis can be used for ppt of lyophibic colloid
A.Brownian motion of colloidal particles depend on the size of particles 
B.Adsorption is exothermic process
C.Colloidal medicines are better because of their large surface area.
D.Electrophoresis can be used for ppt of Iyophobic colloid.

Which of the following will scatter light?

  1. Blood

  2. Starch

  3. Soap solution

  4. All of these


Correct Option: D
Explanation:

Colloidal Solution: blood, starch, Milk, soap solution
True solution: sugar sol, salt sol
Only colloidal solution scatter light.

The average size of the colloids is of the order of:

  1. $10^{-12}:m$ to $10^{-19}:m$

  2. $10^{-7}:m$ to $10^{-9}:m$

  3. $10^{-9}:m$ to $10^{-12}:m$

  4. $10^{-6}:m$ to $10^{-19}:m$


Correct Option: B
Explanation:

The average size of the colloids is of the order of $10^{-7} :m$ to $10^{-9}:m$.

Colloidal state is homogeneous in nature.

  1. True

  2. False


Correct Option: B
Explanation:

Colloidal solutions can be considered as a heterogeneous system consisting of the following three essential components:
(i) A dispersed phase: It is also known as discontinuous or inner phase. It consists of discrete particles significantly larger than ordinary molecules and in this small particles of solute is diffused in solvent.
(ii) A dispersion medium: It is the medium in which dispersed phase is present. This consists of continuously interlinked molecules.
(iii) A stabilising agent: This is a substance which tends to keep the colloidal particles apart. Some colloids are self stabilizers.