Explain the solubility rule “like dissolves like”
Question: Explain the solubility rule like dissolves like in terms of intermolecular forces that exist in solutions. Solution: Like dissolves like means that a solute dissolves in a solvent if their intermolecular interactions are similar. That is if polar solutes can dissolve in polar solvents and non-polar solutes can dissolve in non-polar solvents....
Read More →Explain why on the addition of 1 mol of NaCl
Question: Explain why on the addition of 1 mol of NaCl to 1 litre of water, the boiling point of water increases, while the addition of 1 mol of methyl alcohol to one litre of water decreases its boiling point. Solution: On addition of 1 mol of NaCl to 1 litre of water, the boiling point of water increases, while the addition of 1 mol of methyl alcohol to one litre of water decreases its boiling point because if a non-volatile solute like NaCl is added this happens. Methyl alcohol is volatile th...
Read More →Let A be the set of all triangles in a plane. Show that the relation
Question: Let $A$ be the set of all triangles in a plane. Show that the relation $\mathrm{R}=\left\{\left(\Delta_{1}, \Delta_{2}\right): \Delta_{1} \sim \Delta_{2}\right\}$ is an equivalence relation on $\mathrm{A} .$ Solution: Let $R=\left\{\left(\Delta_{1}, \Delta_{2}\right): \Delta_{1} \sim \Delta_{2}\right\}$ be a relation defined on $A$. Now $\underline{R}$ is Reflexive if $(\Delta, \Delta) \in \underline{R} \underline{\forall} \Delta \underline{A}$ We observe that for each $\Delta \in$ A w...
Read More →Components of a binary mixture of two liquids A and B
Question: Components of a binary mixture of two liquids A and B were being separated by distillation. After some time separation of components stopped and the composition of the vapour phase became the same as that of a liquid phase. Both the components started coming in the distillate. Explain why this happened. Solution: Both the components started coming in the distillate and the vapour and liquid phase will have the same composition. This shows an azeotropic mixture. Therefore it cant be sep...
Read More →Colligative properties are observed
Question: Colligative properties are observed when _____________. (i) a non-volatile solid is dissolved in a volatile liquid. (ii) a non-volatile liquid is dissolved in another volatile liquid. (iii) a gas is dissolved in non-volatile liquid. (iv) a volatile liquid is dissolved in another volatile liquid. Solution: Option (i) a non-volatile solid is dissolved in a volatile liquid and (ii)a non-volatile liquid is dissolved in another volatile liquid are the answers....
Read More →In isotonic solutions ________________.
Question: In isotonic solutions ________________. (i) solute and solvent both are same. (ii) osmotic pressure is the same. (iii) solute and solvent may or may not be same. (iv) a solute is always the same solvent may be different. Solution: Option (ii) and (iii) are the answers....
Read More →Evaluate the integral
Question: Evaluate the integral $\int \frac{1}{1-\tan x} d x$ Solution: Ideas required to solve the problems: * Integration by substitution: A change in the variable of integration often reduces an integral to one of the fundamental integration. If derivative of a function is present in an integration or if chances of its presence after few modification is possible then we apply integration by substitution method. * Knowledge of integration of fundamental functions like sin, cos, polynomial, log...
Read More →Which of the following binary mixtures
Question: Which of the following binary mixtures will have the same composition in the liquid and vapour phase? (i) Benzene Toluene (ii) Water-Nitric acid (iii) Water-Ethanol (iv) n-Hexane n-Heptane Solution: Option (ii) Water-Nitric acid and (iii)Water-Ethanol are the answers....
Read More →Isotonic solutions must have the same _____________.
Question: Isotonic solutions must have the same _____________. (i) solute (ii) density (iii) elevation in boiling point (iv) depression in freezing point Solution: Option (iii)elevation in boiling point and (iv)depression in freezing point are the answers....
Read More →Define a relation on a set. What do you mean by the domain and range of a relation?
Question: Define a relation on a set. What do you mean by the domain and range of a relation? Give an example. Solution: Relation: Let $A$ and $B$ be two sets. Then a relation $R$ from set $A$ to set $B$ is a subset of $A \times B$. Thus, $R$ is a relation to $A$ to $B \Leftrightarrow R \subseteq A \times B$. If $R$ is a relation from a non-void set $B$ and if $(a, b) \in R$, then we write $a$ R b which is read as ' $a$ is related to $b$ by the relation $R^{\prime}$. if $(a, b) \notin R$, then w...
Read More →Van’t Hoff factor i is given by
Question: Vant Hoff factor i is given by the expression _____________. (i) i = Normal molar mass/Abnormal molar mass (ii) i = Abnormal molar mass/ Normal molar mass (iii) i= Observed colligative property/calculated colligative property (iv) i = Calculated colligative property/ Observed colligative property Solution: Option (i)i = Normal molar mass/Abnormal molar mass and (iii)i= Observed colligative property/calculated colligative property are the answers....
Read More →Relative lowering of vapour pressure is a colligative
Question: Relative lowering of vapour pressure is a colligative property because _____________. (i) It depends on the concentration of a non-electrolyte solute in a solution and does not depend on the nature of the solute molecules. (ii) It depends on a number of particles of electrolyte solute in a solution and does not depend on the nature of the solute particles. (iii) It depends on the concentration of a non-electrolyte solute in solution as well as on the nature of the solute molecules. (iv...
Read More →Intermolecular forces between two benzene molecules
Question: Intermolecular forces between two benzene molecules are near to same strength as those between two toluene molecules. For a mixture of benzene and toluene, which of the following are not true? (i) ∆mix H = zero (ii) ∆mix V = zero (iii) These will form a minimum boiling azeotrope. (iv) These will not form the ideal solution. Solution: Option (iii) These will form a minimum boiling azeotropeand (iv)These will not form the ideal solution are the answers....
Read More →Solve this
Question: Let $A=\{1,2,3,4,5,6)$ and let $R=\{(a, b): a, b \in A$ and $b=a+1\}$. Show that $R$ is (i) not reflexive, (ii) not symmetric and (iii) not transitive. Solution: Given that, $A=\{1,2,3,4,5,6)$ and $R=\{(a, b): a, b \in A$ and $b=a+1\}$ $\therefore \mathrm{R}=\{(1,2),(2,3),(3,4),(4,5),(5,6)\}$ Now, $\mathrm{R}$ is Reflexive if $(\mathrm{a}, \mathrm{a}) \in \mathrm{R} \forall \mathrm{a} \in \mathrm{A}$ Since, $(1,1),(2,2),(3,3),(4,4),(5,5),(6,6) \notin \mathrm{R}$ Thus, $R$ is not reflex...
Read More →Which of the following factor (s)
Question: Which of the following factor (s) affect the solubility of a gaseous solute in the a fixed volume of liquid solvent? (a) nature of solute (b) temperature (c) pressure (i) (a) and (c) at constant T (ii) (a) and (b) at constant P (iii) (b) and (c) only (iv) (c) only Solution: Option (i) and (ii) are the answers....
Read More →KH value for Ar(g), CO2(g),
Question: KH value for Ar(g), CO2(g), HCHO (g) and CH4(g) are 40.39, 1.67, 1.83105 and 0.413 respectively. Arrange these gases in the order of their increasing solubility. (i) HCHO CH4 CO2 Ar (ii) HCHO CO2 CH4 Ar (iii) Ar CO2 CH4 HCHO (iv) Ar CH4 CO2 HCHO Solution: Option (iii)Ar CO2 CH4 HCHOis the answer....
Read More →Evaluate the integral
Question: Evaluate the integral $\int \frac{1}{1-\cot x} d x$ Solution: Ideas required to solve the problems: * Integration by substitution: A change in the variable of integration often reduces an integral to one of the fundamental integration. If derivative of a function is present in an integration or if chances of its presence after few modification is possible then we apply integration by substitution method. * Knowledge of integration of fundamental functions like sin, cos, polynomial, log...
Read More →Evaluate the integral
Question: Evaluate the integral $\int \frac{1}{1-\cot x} d x$ Solution: Ideas required to solve the problems: * Integration by substitution: A change in the variable of integration often reduces an integral to one of the fundamental integration. If derivative of a function is present in an integration or if chances of its presence after few modification is possible then we apply integration by substitution method. * Knowledge of integration of fundamental functions like sin, cos, polynomial, log...
Read More →On the basis of information given below mark the correct option.
Question: On the basis of information given below mark the correct option. Information: On adding acetone to methanol some of the hydrogen bonds between methanol molecules break. (i) At specific composition, methanol-acetone mixture will form minimum boiling azeotrope and will show positive deviation from Raoults law. (ii) At specific composition, methanol-acetone mixture forms maximum boiling azeotrope and will show positive deviation from Raoults law. (iii) At specific composition, methanol-ac...
Read More →4L of 0.02 M aqueous solution of NaCl
Question: 4L of 0.02 M aqueous solution of NaCl was diluted by adding one litre of water. The molality of the resultant solution is _____________. (i) 0.004 (ii) 0.008 (iii) 0.012 (iv) 0.016 Solution: Option (iv)0.016is the answer....
Read More →Evaluate the integral
Question: Evaluate the integral $\int \frac{1}{1-\cot x} d x$ Solution: Ideas required to solve the problems: * Integration by substitution: A change in the variable of integration often reduces an integral to one of the fundamental integration. If derivative of a function is present in an integration or if chances of its presence after few modification is possible then we apply integration by substitution method. * Knowledge of integration of fundamental functions like sin, cos, polynomial, log...
Read More →If two liquids A and B form minimum boiling azeotrope
Question: If two liquids A and B form minimum boiling azeotrope at some specific composition then _______________. (i) AB interactions are stronger than those between AA or BB. (ii) vapour pressure of solution increases because more number of molecules of liquids A and B can escape from the solution. (iii) vapour pressure of solution decreases because less number of molecules of only one of the liquids escape from the solution. (iv) AB interactions are weaker than those between AA or BB. Solutio...
Read More →On the set S of all real numbers, define a relation
Question: On the set $S$ of all real numbers, define a relation $R=\{(a, b): a \leq b\}$. Show that $R$ is (i) reflexive (ii) transitive (iii) not symmetric. Solution: Let $R=\{(a, b): a \leq b\}$ be a relation defined on $S .$ Now, We observe that any element $x \in S$ is less than or equal to itself. $\Rightarrow(x, x) \in R \forall x \in S$ $\Rightarrow \mathrm{R}$ is reflexive. Let $(x, y) \in R \forall x, y \in S$ $\Rightarrow \mathrm{x}$ is less than or equal to $\mathrm{y}$ But $y$ cannot...
Read More →On the basis of information given below mark the correct option.
Question: On the basis of information given below mark the correct option. Information: (A) In bromoethane and chloroethane mixture intermolecular interactions of AA and BB type are nearly the same as AB type interactions. (B) In ethanol and acetone mixture AA or BB type intermolecular interactions are stronger than AB type interactions. (C) In chloroform and acetone mixture AA or BB type intermolecular interactions are weaker than AB type interactions. (i) Solution (B) and (C) will follow Raoul...
Read More →We have three aqueous solutions of NaCl labelled
Question: We have three aqueous solutions of NaCl labelled as A, B and C with concentrations 0.1M, 0.01M and 0.001M, respectively. The value of vant Hoff factor for these solutions will be in the order______. (i) iA iB iC (ii) iA iB iC (iii) iA= iB= iC (iv) iAiB iC Solution: Option (iii)iA= iB= iC is the answer....
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