Surface Chemistry

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 :