Solve the following
Question: The $\mathrm{OH}$ concentration in a mixture of $5.0 \mathrm{~mL}$ of $0.0504 \mathrm{M} \mathrm{NH}_{4} \mathrm{Cl}$ and $2 \mathrm{~mL}$ of $0.0210 \mathrm{M} \mathrm{NH}_{3}$ solution is $x \times 10^{-6} \mathrm{M}$. The value of $x$ is (Nearest integer) [Given $\mathrm{K}_{\mathrm{w}}=1 \times 10^{-14}$ and $\mathrm{K}_{\mathrm{b}}=1.8 \times 10^{-5}$ ] Solution: $\left[\mathrm{NH}_{4}^{+}\right]=0.0504 \\left[\mathrm{NH}_{3}\right]=0.0210$ So $\mathrm{K}_{\mathrm{b}}=\frac{\left[...
Read More →The characteristics of elements X, Y and Z with atomic numbers, respectively, 33, 53 and 83 are :
Question: The characteristics of elements X, Y and Z with atomic numbers, respectively, 33, 53 and 83 are :$\mathrm{X}$ and $\mathrm{Y}$ are metalloids and $\mathrm{Z}$ is a metal.$\mathrm{X}$ is a metalloid, $\mathrm{Y}$ is a non-metal and $\mathrm{Z}$ is a metal.$\mathrm{X}, \mathrm{Y}$ and $\mathrm{Z}$ are metals.$\mathrm{X}, \mathrm{Y}$ and $\mathrm{Z}$ are metals.Correct Option: , 2 Solution: $\mathrm{X}={ }_{33} \mathrm{As} \rightarrow$ Metalloid $\mathrm{Y}={ }_{53} \mathrm{I} \rightarrow...
Read More →Prove the following
Question: Considen the given reaction, percentage yield of : $\mathrm{C}\mathrm{A}\mathrm{B}$$\mathrm{B}\mathrm{C}\mathrm{A}$$ACB$$\mathrm{C}\mathrm{B}\mathrm{A}$Correct Option: 4, Solution:...
Read More →Of the following four aqueous solutions,
Question: Of the following four aqueous solutions, total number of those solutions whose freezing point is lower than that of $0.10 \mathrm{M} \mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}$ is (Integer answer)$0.10 \mathrm{M} \mathrm{Ba}_{3}\left(\mathrm{PO}_{4}\right)_{2}$$0.10 \mathrm{M} \mathrm{Na}_{2} \mathrm{SO}_{4}$$0.10 \mathrm{M} \mathrm{KCl}$$0.10 \mathrm{M} \mathrm{Li}_{3} \mathrm{PO}_{4}$Correct Option: , 4 Solution: As $0.1 \mathrm{M} \mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}$ is non-dis...
Read More →Solve this following
Question: Consider the above reaction. The percentage yield of amide product is (Round off to the Nearest Integer). (Given : Atomic mass : $\mathrm{C}: 12.0 \mathrm{u}, \mathrm{H}: 1.0 \mathrm{u}$, $\mathrm{N}: 14.0 \mathrm{u}, \mathrm{O}: 16.0 \mathrm{u}, \mathrm{Cl}: 35.5 \mathrm{u})$ Solution: $\therefore 0.140 \mathrm{gm} \quad \frac{169}{140.5} \times 0.140$ $\begin{array}{ll}\text { L.R. } =0.168 \mathrm{gm}0.388 \mathrm{gm}\end{array}$ excess $\therefore$ Theoretical amount of given produ...
Read More →Which of the following is least basic ?
Question: Which of the following is least basic ?$\left(\mathrm{CH}_{3} \mathrm{CO}\right) \ddot{\mathrm{N}} \mathrm{HC}_{2} \mathrm{H}_{5}$$\left(\mathrm{C}_{2} \mathrm{H}_{5}\right)_{3} \ddot{\mathrm{N}}$$\left(\mathrm{CH}_{3} \mathrm{CO}\right)_{2} \ddot{\mathrm{N}} \mathrm{H}$$\left(\mathrm{C}_{2} \mathrm{H}_{5}\right)_{2} \ddot{\mathrm{N}} \mathrm{H}$Correct Option: , 3 Solution: For the given compounds : (Hence least basic) (4) $\mathrm{CH}_{3}-\mathrm{CH}_{2}-\ddot{\mathrm{NH}}-\mathrm{CH...
Read More →These are physical properties of an element
Question: These are physical properties of an element (A) Sublimation enthalpy (B) Ionisation enthalpy (C) Hydration enthalpy (D) Electron gain enthalpy The total number of above properties that affect the reduction potential is (Integer answer) Solution: Sublimation enthalpy, Ionisation enthalpy and hydration enthalpy affect the reduction potential....
Read More →Given below are two statements:
Question: Given below are two statements: Statement I : Bohr's theory accounts for the stability and line spectrum of $\mathrm{Li}^{+}$ ion. Statement II : Bohr's theory was unable to explain the splitting of spectral lines in the presence of a magnetic field. In the light of the above statements, choose the most appropriate answer from the options given below :Both statement I and statement II are true.Statement $\mathrm{I}$ is false but statement $\mathrm{II}$ is true.Both statement I and stat...
Read More →Solve the following
Question: $\mathrm{AB}_{3}$ is an interhalogen T-shaped molecule. The number of lone pairs of electrons on $\mathrm{A}$ is (Integer answer) Solution: T-shaped molecule means 3 sigma bond and 2 lone pairs of electron on central atom....
Read More →The secondary valency and the number of hydrogen bonded
Question: The secondary valency and the number of hydrogen bonded water molecule(s) in $\mathrm{CuSO}_{4} \cdot 5 \mathrm{H}_{2} \mathrm{O}$, respectively, are :6 and 44 and 16 and 55 and 1Correct Option: , 2 Solution:...
Read More →Solve this following
Question: Consider the reaction $\mathrm{N}_{2} \mathrm{O}_{4}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{NO}_{2}(\mathrm{~g})$. The temperature at which $\mathrm{K}_{\mathrm{C}}=20.4$ and $\mathrm{K}_{\mathrm{P}}=600.1$, is $\mathrm{K}$. (Round off to the Nearest Integer). [Assume all gases are ideal and $\mathrm{R}=0.0831 \mathrm{~L}$ bar $\mathrm{K}^{-1} \mathrm{~mol}^{-1}$ ] Solution: $\mathrm{N}_{2} \mathrm{O}_{4}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{NO}_{2}(\mathrm{~g}) ; \Delta \mathr...
Read More →An unsaturated hydrocarbon X on ozonolysis gives A.
Question: An unsaturated hydrocarbon X on ozonolysis gives A. Compound A when warmed with ammonical silver nitrate forms a bright silver mirror along the sides of the test tube. The unsaturated hydrocarbon $X$ is :Correct Option: 3, Solution: As (A) compound given positive tollen's test hence it may consist-CHO (aldehyde group). or it can be $\mathrm{HCOOH}$ So for the given option : and for other compounds (options):...
Read More →Excess of isobutane on reaction
Question: Excess of isobutane on reaction with $\mathrm{Br}_{2}$ in presence of light at $125^{\circ} \mathrm{C}$ gives which one of the following, as the major product?Correct Option: , 4 Solution:...
Read More →Solve this following
Question: $\mathrm{KBr}$ is doped with $10^{-5}$ mole percent of $\mathrm{SrBr}_{2}$. The number of cationic vacancies in $1 \mathrm{~g}$ of $\mathrm{KBr}$ crystal is $10^{14}$. (Round off to the Nearest Integer). [Atomic Mass : $\mathrm{K}: 39.1 \mathrm{u}, \mathrm{Br}: 79.9 \mathrm{u}$, $\left.\mathrm{N}_{\mathrm{A}}=6.023 \times 10^{23}\right]$ Solution: 1 mole $\mathrm{KBr}(=119 \mathrm{gm})$ have $\frac{10^{-5}}{100}$ moles $\mathrm{SrBr}_{2}$ and hence, $10^{-7}$ moles cation vacancy (as $...
Read More →The first ionization energy of magnesium is smaller
Question: The first ionization energy of magnesium is smaller as compared to that of elements $\mathrm{X}$ and $\mathrm{Y}$, but higher than that of $Z$. the elements $X, Y$ and $Z$, respectively, are:chlorine, lithium and sodiumargon, lithium and sodiumargon, chlorine and sodiumneon, sodium and chlorineCorrect Option: , 3 Solution: The $1^{\text {st }}$ IE order of $3^{\text {rd }}$ period is $\mathrm{Na}\mathrm{Al}\mathrm{Mg}\mathrm{Si}\mathrm{S}\mathrm{P}\mathrm{Cl}\mathrm{Ar}$ $\mathrm{X} \ ...
Read More →Excess of isobutane on reaction
Question: Excess of isobutane on reaction with $\mathrm{Br}_{2}$ in presence of light at $125^{\circ} \mathrm{C}$ gives which one of the following, as the major product?Correct Option: , 4 Solution:...
Read More →An organic compound "A" on treatment with benzene sulphonyl chloride
Question: An organic compound "A" on treatment with benzene sulphonyl chloride gives compound B. B is soluble in dil. $\mathrm{NaOH}$ solution. Compound $\mathrm{A}$ is :$\mathrm{C}_{6} \mathrm{H}_{5}-\mathrm{N}-\left(\mathrm{CH}_{3}\right)_{2}$$\mathrm{C}_{6} \mathrm{H}_{5}-\mathrm{NHCH}_{2} \mathrm{CH}_{3}$$\mathrm{C}_{6} \mathrm{H}_{5}-\mathrm{CH}_{2} \mathrm{NHCH}_{3}$Correct Option: , 4 Solution: Hinsberg reagent (Benzene sulphonyl chloride) gives reaction product with $1^{\circ}$ amine and...
Read More →The incorrect statement is:
Question: The incorrect statement is:$\mathrm{Cl}_{2}$ is more reactive than $\mathrm{ClF}$.$\mathrm{F}_{2}$ is more reactive than $\mathrm{ClF}$.On hydrolysis $\mathrm{ClF}$ froms $\mathrm{HOCl}$ and $\mathrm{HF}$.$\mathrm{F}_{2}$ is a stronger oxidizing agent than $\mathrm{Cl}_{2}$ in aqueous solutionCorrect Option: 1 Solution: (i) Reactivity order : $\mathrm{F}_{2}\mathrm{ClF}$ (inter halogen) $\mathrm{Cl}_{2}$ (ii) $\mathrm{ClF}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{HOCl}+\mathrm{HF}...
Read More →The number of chlorine atoms in
Question: The number of chlorine atoms in $20 \mathrm{~mL}$ of chlorine gas at STP is $10^{21}$. (Round off to the Nearest Integer). [Assume chlorine is an ideal gas at STP $\mathrm{R}=0.083 \mathrm{~L}$ bar $\left.\mathrm{mol}^{-1} \mathrm{~K}^{-1}, \mathrm{~N}_{\mathrm{A}}=6.023 \times 10^{23}\right]$ Solution: $\mathrm{PV}=\mathrm{nRT}$ $1.0 \times \frac{20}{1000}=\frac{\mathrm{N}}{6.023 \times 10^{23}} \times 0.083 \times 273$ $\therefore$ Number of $\mathrm{Cl}_{2}$ molecules, $\mathrm{N}=5...
Read More →Deficiency of vitamin K causes :
Question: Deficiency of vitamin $K$ causes :Increase in blood clotting timeIncrease in fragility of $R B C$ 'sCheilosisDecrease in blood clotting timeCorrect Option: 1 Solution: Due to deficiency of Vitmain $K$ causes increases in blood clotting time. Note : Vitamin K related to blood factor....
Read More →Given below are two statements.
Question: Given below are two statements. Statement I: Frenkel defects are vacancy as well as interstitial defects. Statement II: Frenkel defect leads to colour in ionic solids due to presence of F-centres. Choose the most appropriate answer for the statements from the options given below:Statement I is false but Statement II is trueBoth Statement I and Statement II are trueStatement I is true but Statement II is falseBoth Statement I and Statement II are falseCorrect Option: , 3 Solution: Theor...
Read More →Main Products formed during a reaction of
Question: Main Products formed during a reaction of 1-methoxy naphthalene with hydroiodic acid are:Correct Option: , 2 Solution:...
Read More →The correct sequential addition
Question: The correct sequential addition of reagents in the preparation of 3-nitrobenzoic acid from benzene is:$\mathrm{Br}_{2} / \mathrm{AlBr}_{3}, \mathrm{HNO}_{3} / \mathrm{H}_{2} \mathrm{SO}_{4}, \mathrm{Mg} / \mathrm{ether}, \mathrm{CO}_{2}, \mathrm{H}_{3} \mathrm{O}^{+}$$\mathrm{Br}_{2} / \mathrm{AlBr}_{3}, \mathrm{NaCN}, \mathrm{H}_{3} \mathrm{O}^{+}, \mathrm{HNO}_{3} / \mathrm{H}_{2} \mathrm{SO}_{4}$$\mathrm{Br}_{2} / \mathrm{AlBr}_{3}, \mathrm{HNO}_{3} / \mathrm{H}_{2} \mathrm{SO}_{4},...
Read More →Given below are two statements.
Question: Given below are two statements. Statement I: According to Bohr's model of an atom, qualitatively the magnitude of velocity of electron increases with decrease in positive charges on the nucleus as there is no strong hold on the electron by the nucleus. Statement II: According to Bohr's model of an atom, qualitatively the magnitude of velocity of electron increases with decrease in principal quantum number. In the light of the above statements, choose the most appropriate answer from th...
Read More →What are the products formed
Question: What are the products formed in sequence when excess of $\mathrm{CO}_{2}$ is passed in slaked lime?$\mathrm{Ca}\left(\mathrm{HCO}_{3}\right)_{2}, \mathrm{CaCO}_{3}$$\mathrm{CaCO}_{3}, \mathrm{Ca}\left(\mathrm{HCO}_{3}\right)_{2}$$\mathrm{CaO}, \mathrm{Ca}\left(\mathrm{HCO}_{3}\right)_{2}$$\mathrm{CaO}, \mathrm{CaCO}_{3}$Correct Option: , 2 Solution: $\mathrm{Ca}(\mathrm{OH})_{2}+\mathrm{CO}_{2} \longrightarrow \mathrm{CaCO}_{3} \downarrow+\mathrm{H}_{2} \mathrm{O}$ $\mathrm{CaCO}_{3} \...
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