Surface Chemistry

The correct option among the following is :

Tyndall effect is more effectively shown by :

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : In expensive scientific instruments, silica gel is kept in watch-glasses or in semipermeable membrane bags. Reason (R) : Silica gel adsorbs moisture from air via adsorption, thus protects the instrument from water corrosion (rusting) and / or prevents malfunctioning. In the light of the above statements, choose the correct answer from the options given below :

A colloidal system consisting of a gas dispersed in a solid is called a/an :

'Adsorption' principle is used for which of the following purification method?

The adsorbent used in adsorption chromatography is/are - A. silica gel B. alumina C. quick lime D. magnesia Choose the most appropriate answer from the options given below :

Which of the following is not an example of heterogenous catalytic reaction?

Match the catalysts (Column I) with products (Column II). .tg {border-collapse:collapse;border-spacing:0;width:100%} .tg td{font-family:Arial, sans-serif;font-size:14px;padding:10px 5px;border-style:solid;border-width:1px;overflow:hidden;word-break:normal;border-color:black;} .tg th{font-family:Arial, sans-serif;font-size:14px;font-weight:normal;padding:10px 5px;border-style:solid;border-width:1px;overflow:hidden;word-break:normal;border-color:black;} .tg .tg-s6z2{text-align:center} .tg .tg-baqh{text-align:center;vertical-align:top} .tg .tg-hgcj{font-weight:bold;text-align:center} Column I Column II (A) V₂O₅ (i) Polyethylene (B) TiCl₄/Al(Me)₃ (ii) ethanal (C) PdCl₂ (iii) H₂SO₄ (D) Iron Oxide (iv) NH₃

For the following Assertion and Reason, the correct option is Assertion : For hydrogenation reactions, the catalytic activity increases from Group 5 to Group 11 metals with maximum activity shown by Group 7-9 elements. Reason : The reactants are most strongly adsorbed on group 7-9 elements.

Match List - I with List - II. .tg {border-collapse:collapse;border-spacing:0;} .tg td{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px; overflow:hidden;padding:10px 5px;word-break:normal;} .tg th{border-color:black;border-style:solid;border-width:1px;font-family:Arial, sans-serif;font-size:14px; font-weight:normal;overflow:hidden;padding:10px 5px;word-break:normal;} .tg .tg-c3ow{border-color:inherit;text-align:center;vertical-align:top} .tg .tg-7btt{border-color:inherit;font-weight:bold;text-align:center;vertical-align:top} .tg .tg-fymr{border-color:inherit;font-weight:bold;text-align:left;vertical-align:top} .tg .tg-0pky{border-color:inherit;text-align:left;vertical-align:top} List - I Reaction List - II Catalyst (A) $4N{H_3}(g) + 5{O_2}(g) \to 4NO(g) + 6{H_2}O(g)$ (I) $NO(g)$ (B) ${N_2}(g) + 3{H_2}(g) \to 2N{H_3}(g)$ (II) ${H_2}S{O_4}(l)$ (C) ${C_{12}}{H_{22}}{O_{11}}(aq) + {H_2}O(l) \to \mathop {{C_6}{H_{12}}{O_6}}\limits_{Glu\cos e} + \mathop {{C_6}{H_{12}}{O_6}}\limits_{Fructose}$ (III) $Pt(s)$ (D) $2S{O_2}(g) + {O_2}(g) \to 2S{O_3}(g)$ (IV) $Fe(s)$ Choose the correct answer from the options given below :

Alum helps in purifying water by :

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?

The volume of a colloidal particle, V_C as compared to the volume of a solute particle in a true solution V_S, could be

Gold numbers of protective colloids A, B, C and D are 0.50, 0.01, 0.10 and 0.005, respectively. The correct order of their protective powers is

The coagulating power of electrolytes having ions Na⁺, Al³⁺ and Ba²⁺ for arsenic sulphide sol increases in the order:

The most appropriate method of making egg-albumin sol is :

Gold numbers of some colloids are : Gelatin : 0.005 - 0.01, Gum Arabic : 0.15 - 0.25; Oleate : 0.04 - 1.0; Starch : 15 - 25. Which among these is a better protective colloid ?

The Tyndall effect is observed only when following conditions are satisfied: (a) The diameter of the dispersed particles is much smaller than the wavelength of the light used. (b) The diameter of the dispersed particle is not much smaller than the wavelength of the light used. (c) The refractive indices of the dispersed phase and dispersion medium are almost similar in magnitude. (d) The refractive indices of the dispersed phase and dispersion medium differ greatly in magnitude.

Among the following, correct statement is :

Which of the following statements about colloids is False ?