Associated colloid among the following is
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Solution
Sodium stearate is a soap. Soaps and detergents are surface agents which when dissolved in a medium,forms aggregated particles, called associated colloids.
A colloidal solution is subjected to an electric field. The particles move towards anode. The coagulation of same sol is studied using NaCl, BaCl2 and AlCl3 solutions. The order of their coagulation power should be–
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Solution
As colloidal particles move towards anode so these particles are negatively charged and coagulated by cations of electrolyte.According to Hardy Schulze rule,
Coagulation power ∝ charge of ion
∴ Order of coagulation power is Al3+ > Ba2+> > Na+
Which is adsorbed in maximum amount by activated charcoal ?
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Solution
The gases having higher values for critical temperature are easily liquified and are adsorbed to the greater extent.CO2 has highest critical temperature of 304K.
The function of gum arabic in the preparation of an Indian ink is
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Solution
Gum arabic has protective power.
In petrochemical industry alcohols are directly converted to gasoline by passing over heated
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Solution
ZSM-5 is a shape selective catalyst. Zeolites are good shape selective catalysts because of the honey comb like structure
Alum helps in purifying water by
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Solution
Alum coagulates mud particles and helps in purifying water.
The disperse phase in colloidal iron (III) hydroxide and colloidal gold is positively and negatively charged,respectively. Which of the following statements is NOT correct?
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Solution
When oppositely charged sols are mixed their charges are neutralised. Both sols may be partially or completely precipitated.
Which of the following is most powerful to coagulate the negative colloid?
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Solution
According to Hardy-Schulze rule "The amount of electrolyte required to coagulate a fixed amount of a sol depends upon the sign of charge and valency of the flocculating ion."Thus,the coagulating power vary in the order.Al3+ > Zn++ > Na+
The dispersed phase and dispersion medium in soap lather are respectively
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Solution
Soap lather is a colloid containing gas as a dispersed phase and liquid as a dispersion medium.
Which one of the following impurities present in colloidal solution cannot be removed by electrodialysis?
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Solution
Electrodialysis involves movement of ions towards oppositely charged electrodes.Urea being a covalent compound does not dissociate to give ions and hence it cannot be removed by electrodialysis.However all the other given compounds are ionic which can undergo dissociation to give oppositely charged ions and thus can be separated.