Colloids: classification and preparation

26 questions on Colloids: classification and preparation from the Surface Chemistry chapter: 5 NEET level, 10 JEE Main, 11 JEE Advanced. Each one opens with its answer and solution.

• Fog is a colloidal system in which the dispersed phase and the dispersion medium are, respectively, NEET level
• Milk is an example of a colloid of the type NEET level
• Which of the following sols is lyophobic in nature? NEET level
• Bredig's arc method is mainly used for preparing colloidal sols of NEET level
• The size of the particles in a colloidal system lies in the range NEET level
• Assertion (A): Lyophilic sols are more stable than lyophobic sols. Reason (R): The particles of a lyophilic sol are extensively solvated by the dispersion mediu... JEE Main level
• Starch in water, sulphur sol and soap solution above its critical micelle concentration are classified, respectively, as JEE Main level
• When a few drops of concentrated FeCl3 solution are added to boiling water, a reddish-brown sol is formed. This preparation is an example of JEE Main level
• Which of the following statements about soap micelles in water is correct? JEE Main level
• Select the correct pairings of colloidal system and type. JEE Main level
• Which of the following preparations are condensation methods? JEE Main level
• A student prepares an Fe(OH)3 sol by adding 4.00 mL of 0.40 M FeCl3 to boiling water. Assuming complete hydrolysis, FeCl3 + 3H2O -> Fe(OH)3 + 3HCl, find the mas... JEE Main level
• Gold of density 19.3 g cm^-3 is dispersed as spherical particles of radius 15 nm. Find the number of particles in 1.00 g of gold, in units of 10^15, to the near... JEE Main level
• In a micellar solution of a soap, the critical micelle concentration is 1.0x10^-3 M and each micelle contains 80 soap anions. Assuming that all soap above the C... JEE Main level
• A macromolecular colloid is dissolved at 5.00 g L^-1 in water and gives an osmotic pressure of 118.0 Pa at 298 K. Using pi = cRT with c in mol m^-3 and R = 8.31... JEE Main level
• A sol is prepared by adding 20 mL of 0.10 M KI to 15 mL of 0.10 M AgNO3. Which row correctly gives the charge on the AgI particles and a coagulant that would be... JEE Advanced level
• Samples I to IV are emulsions. I mixes readily with water and conducts electricity well. II mixes readily with kerosene but not with water, and oil-soluble Suda... JEE Advanced level
• Equal masses (1.0 g L^-1) of the following are dissolved separately in water: urea (M = 60), NaCl (M = 58.5, assume complete dissociation), a macromolecular col... JEE Advanced level
• A given mass of gold is dispersed first as spherical particles of radius r and then as spherical particles of radius 2r (same total mass, same density). Select ... JEE Advanced level
• A sol is made by mixing 50 mL of 0.10 M AgNO3 with 30 mL of 0.10 M KI (Ag = 108, I = 127). Select the correct statements. JEE Advanced level
• A soap solution contains 0.050 M soap with CMC = 1.0x10^-3 M and aggregation number 98. Take N_A = 6.022x10^23 mol^-1 and assume all soap above the CMC is micel... JEE Advanced level
• Select the correct classifications of the colloids. JEE Advanced level
• A silver sol is prepared by dispersing 2.16 g of silver (density 10.5 g cm^-3) into identical spherical particles of radius 20 nm (1 nm = 10^-7 cm). Find the to... JEE Advanced level
• A protein sol containing 8.0 g L^-1 of the protein supports a water column of height 3.2 cm at osmotic equilibrium at 300 K. Take the density of water as 1000 k... JEE Advanced level
• A colloidal AgI sol is made by mixing 32 mL of 0.018 M KI with 20 mL of 0.015 M AgNO3. Assuming complete precipitation of AgI, find the concentration of unreact... JEE Advanced level
• A macromolecular colloid of molar mass 48000 g mol^-1 is dissolved (2.4 g) in 100 g of water at a temperature where the vapour pressure of pure water is 23.76 m... JEE Advanced level