Mark the tick against the correct answer in the following:
Question: Mark the tick against the correct answer in the following: Let $\mathrm{Q}^{+}$be the set of all positive rationals. Then, the operation $*$ on $\mathrm{Q}^{+}$defined by $\mathrm{a} * \mathrm{~b}=\frac{\mathrm{ab}}{2}$ for $\mathrm{all} \mathrm{a}, \mathrm{b} \in \mathrm{Q}^{+}$ is A. commutative but not associative B. associative but not commutative C. neither commutative nor associative D. both commutative and associative Solution: According to the question, $\mathrm{Q}=\{$ Positive...
Read More →What type of solutions are formed
Question: What type of solutions are formed on dissolving different concentrations of soap in the water? Solution: Soap solution at low concentration behaves like normal electrolytic solution. But at high concentration soap solution behaves as associated colloid and form micelles....
Read More →Why is chemisorption referred
Question: Why is chemisorption referred to as activated adsorption? Solution: Chemisorption involves chemical bond formation which requires activation energy. That is why it is referred to as activated adsorption...
Read More →Why is it important to have a clean
Question: Why is it important to have a clean surface in surface studies? Solution: In the adsorption process, the surface of adsorbent adsorbs the desired gases. If the surface is already occupied by some other gases, it becomes saturated and thus cannot adsorb desired gases...
Read More →Which of the following phenomenon occurs
Question: Which of the following phenomenon occurs when a chalk stick is dipped in ink? (i) adsorption of coloured substance (ii) adsorption of solvent (iii) absorption and adsorption both of solvent (iv) absorption of solvent Solution: Option (i) and (iv) are the answers....
Read More →In a reaction, catalyst changes ____________.
Question: In a reaction, catalyst changes ____________. (i) physically (ii) qualitatively (iii) chemically (iv) quantitatively Solution: Option (i)physically and (ii)qualitatively are the answers....
Read More →Which phenomenon occurs
Question: Which phenomenon occurs when an electric field is applied to a colloidal solution and electrophoresis is prevented? (i) Reverse osmosis takes place. (ii) Electroosmosis takes place. (iii) Dispersion medium begins to move. (iv) Dispersion medium becomes stationary. Solution: Option (ii) and (iii) are the answers....
Read More →Evaluate the following integrals:
Question: Evaluate the following integrals: $\int e^{\sqrt{x}} d x$ Solution: Let $I=\int e^{\sqrt{x}} d x$ $\sqrt{\mathrm{X}}=\mathrm{t} ; \mathrm{X}=\mathrm{t}^{2}$ $\mathrm{d} \mathrm{x}=2 \mathrm{tdt}$ $I=2 \int e^{t} t d t$ Using integration by parts, $I=2\left(t \int e^{t} d t-\int \frac{d}{d t} t \int e^{t} d t\right)$ $=2\left(t e^{t}-\int e^{t} d t\right)$ $=2\left(t e^{t}-e^{t}\right)+c$ $=2 e^{t}(t-1)+c$ Replace the value of $\mathrm{t}$ $=2 e^{\sqrt{x}}(\sqrt{x}-1)+c$...
Read More →What happens when a lyophilic sol is added
Question: What happens when a lyophilic sol is added to a lyophobic sol? (i) Lyophobic sol is protected. (ii) Lyophilic sol is protected. (iii) Film of lyophilic sol is formed over lyophobic sol. (iv) Film of lyophobic sol is formed over lyophilic sol. Solution: Option (i) Lyophobic sol is protected and (iii)Film of lyophilic sol is formed over lyophobic sol are the answers....
Read More →Which of the following colloids cannot
Question: Which of the following colloids cannot be coagulated easily? (i) Lyophobic colloids. (ii) Irreversible colloids. (iii) Reversible colloids. (iv) Lyophilic colloids. Solution: Option (iii) and (iv) are the answers....
Read More →Evaluate the following integrals:
Question: Evaluate the following integrals: $\int(\log x)^{2} x d x$ Solution: Let $I=\int(\log x)^{2} x d x$ Using integration by parts, $=(\log x)^{2} \int x d x-\int \frac{d}{d x}(\log x)^{2} \int x d x$ $=(\log x)^{2} \frac{x^{2}}{2}-\int\left(2(\log x)\left(\frac{1}{x}\right) \int x d x\right) d x$ $=\frac{x^{2}}{2}(\log x)^{2}-2 \int(\log x)\left(\frac{1}{x}\right)\left(\frac{x^{2}}{2}\right) d x$ $=\frac{x^{2}}{2}(\log x)^{2}-\int x \log x d x$ Using integration by integration by parts in...
Read More →Which of the following substances will precipitate
Question: Which of the following substances will precipitate the negatively charged emulsions? (i) KCl (ii) glucose (iii) urea (iv) NaCl Solution: Option (i) and (iv) are the answers....
Read More →An emulsion cannot be broken
Question: An emulsion cannot be broken by __________ and ___________. (i) heating (ii) adding more amount of dispersion medium (iii) freezing (iv) adding emulsifying agent Solution: Option (ii) and (iv) are the answers....
Read More →Which of the following statements are correct?
Question: Which of the following statements are correct? (i) Mixing two oppositely charged sols neutralises their charges and stabilises the colloid. (ii) Presence of equal and similar charges on colloidal particles provides stability to the colloids. (iii) Any amount of dispersed liquid can be added to emulsion without destabilising it. (iv) Brownian movement stabilises sols. Solution: Option (ii) and (iv) are the answers....
Read More →H2 gas is adsorbed on activated charcoal
Question: H2 gas is adsorbed on activated charcoal to a very little extent in comparison to easily liquefiable gases due to ____________. (i) very strong van der Waals interaction. (ii) very weak van der Waals forces. (iii) very low critical temperature. (iv) very high critical temperature. Solution: Option (ii) and (iii) are the answers....
Read More →Freundlich adsorption isotherm is given
Question: Freundlich adsorption isotherm is given by the expression x/m =kp1/nwhich of the following conclusions can be drawn from this expression (i) When1/n= 0, the adsorption is independent of pressure. (ii) When 1/n = 0, the adsorption is directly proportional to pressure. (iii)When n = 0,x/m vs p graph is a line parallel to x-axis. (iv) When n = 0, a plot of x/m vs p is a curve. Solution: Option (i) and (iii) are the answers....
Read More →Which of the following statements are
Question: Which of the following statements are correct about solid catalyst? (i) Same reactants may give different product by using different catalysts. (ii) Catalyst does not change ∆H of reaction. (iii) Catalyst is required in large quantities to catalyse reactions. (iv) The catalytic activity of a solid catalyst does not depend upon the strength of chemisorption. Solution: Option (i) and (ii) is the answer....
Read More →Which of the following option are correct?
Question: Which of the following option are correct? (i) Micelle formation by soap in aqueous solution is possible at all temperatures. (ii) Micelle formation by soap in aqueous solution occurs above a particular concentration. (iii) On dilution of soap, solution micelles may revert to individual ions. (iv) Soap solution behaves like a normal strong electrolyte at all concentrations. Solution: Option (ii)Micelle formation by soap in aqueous solution occurs above a particular concentration and (i...
Read More →Which of the following process is not responsible
Question: Which of the following process is not responsible for the presence of electric charge on the sol particles? (i)Electron capture by sol particles. (ii)Adsorption of ionic species from solution. (iii) Formation of Helmholtz electrical double layer. (iv) Absorption of ionic species from solution. Solution: Option (iv)Absorption of ionic species from solutionis the answer....
Read More →Which of the following process is responsible
Question: Which of the following process is responsible for the formation of the delta at a a place where rivers meet the sea? (i) Emulsification (ii) Colloid formation (iii) Coagulation (iv) Peptisation Solution: Option (iii) is the answer....
Read More →Mark the tick against the correct answer in the following:
Question: Mark the tick against the correct answer in the following: Let $a * b=a+a b$ for all $a, b \in Q$. Then, A. * is not a binary composition B. $*$ is not commutative C. $*$ is commutative but not associative D. $*$ is both commutative and associative Solution: According to the question , $\mathrm{Q}=\{\mathrm{a}, \mathrm{b}\}$ $\mathrm{R}=\{(\mathrm{a}, \mathrm{b}): \mathrm{a} * \mathrm{~b}=\mathrm{a}+\mathrm{ab}\}$ Formula $*$ is commutative if $a * b=b * a$ $*$ is associative if $(\mat...
Read More →Arrange the following diagrams in
Question: Arrange the following diagrams in the correct sequence of steps involved in the mechanism of catalysis, in accordance with modern adsorption theory. (i) a b c d e (ii) a c b d e (iii) a c b e d (iv) a b c e d Solution: Option (ii)a c b d e is the answer....
Read More →Mark the tick against the correct answer in the following:
Question: Mark the tick against the correct answer in the following: Let $Q$ be the set of all rational numbers, and $*$ be the binary operation, defined by $a * b=a+2 b$, then A. ${ }^{*}$ is commutative but not associative B. $*$ is associative but not commutative C. $*$ is neither commutative nor associative D. $*$ is both commutative and associative Solution: According to the question, $\mathrm{Q}$ is set of all rarional numbers $R=\{(a, b): a * b=a+2 b\}$ Formula $*$ is commutative if $a * ...
Read More →The values of colligative properties
Question: The values of colligative properties of the colloidal solution are of small order in comparison to those shown by true solutions of same concentration because of colloidal particles __________________. (i) exhibit an enormous surface area. (ii) remain suspended in the dispersion medium. (iii) form lyophilic colloids. (iv) are comparatively less in number Solution: Option (iv) is the answer....
Read More →A colloidal system having a solid
Question: A colloidal system having a solid substance as a dispersed phase and a liquid as a dispersion medium is classified as ____________. (i) solid sol (ii) gel (iii) emulsion (iv) sol Solution: Option (iv) is the answer....
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