AIIMS Chemistry Class 12 Questions

Assertion: $\text{CH}_3 - \underset{\substack{| \\ \text{CH}_3}}{\overset{\substack{\text{CH}_3 \\ |}}{\text{C}}} - \text{O} - \text{CH}_3$ React with HBr to form $(\text{CH}_3)_3\text{CBr}$ and $\text{CH}_3\text{OH}$

Reason: It follows SN1 mechanism

Product is:

Assertion : Glyceraldehyde reacts with 2 2 Br /H Oto form achiral compound

Reason: –CHO and $\text{–CH}_{2}\text{OH}$ both are oxidized

Correct order for reaction with alcoholic KOH

$\text{H}-\overset{\substack{\text{O} \\ ||}}{\text{C}}-\text{H} + \text{CH}_3-\text{CH}=\text{O} \xrightarrow{\text{Conc. NaOH}}$ Find out the products of reaction

For a first order gas phase reaction :

$\text{A}_{(\text{g})} \rightarrow 2\text{B}_{(\text{g})} + \text{C}_{(\text{g})}$

$\text{P}_0$ be initial pressure of A and $\text{P}_t$ the total pressure at time ‘t’. Integrated rate equation is :

Assertion: Two sugar units joined by 1,2-glycosidic bond in sucralose.

Reason: It contains 1 C-glucose and 2 C -fructose glycosidic bond

Out of $\text{BeF}_2, \text{MgF}_2, \text{CaF}_2, \text{SrF}_2$ which has maximum solubility :

Assertion : Glucose does not gives 2,4-DNP test

Reason : Glucose exists in cyclic hemiacetal form

$\left[\text{Co}(\text{C}_2\text{O}_4)_3\right]^{3-}$ is a :

Which is the chemical test for polysaccharide?

Assertion : Phenol reacts with $\text{CH}_3\text{I}$ in presence of $\text{NaOH}$ to form methoxybenzene.

Reason : Phenoxide is better nucleophile than phenol

Assertion: Tert. Butyl amine can be formed by Gabriel phthalimide synthesis

Reason: It follow N S 1 mechanism

(1) $\text{C}_6\text{H}_5-\overset{\substack{\text{O} \\ ||}}{\text{C}}-\text{C}_6\text{H}_5$

(2) $\text{C}_6\text{H}_5-\text{CHO}$

(3) $\text{p}-\text{CH}_3-\text{C}_6\text{H}_4-\text{CHO}$

(4) $\text{p}-\text{CH}_3\text{O}-\text{C}_6\text{H}_4-\text{CHO}$

Which of the following does not give ppt with CrO₄²⁻

$\text{C}_7\text{H}_{10}\text{O}$ reacts with $\text{CH}_3\text{MgBr}$ to give a compound $\text{C}_8\text{H}_{14}\text{O}$ which gives the test with iodoform, then find out structure of A

At 527 °C temperature the activation energy is54.7 KJ/mole . The value of Arrhenius factor is4 $\times 10^{10}$. The rate constant will be

Calculate emf of cell at 25°C

$\text{Cell notation : } \text{M} \mid \text{M}^{2+}_{0.01} \parallel \text{M}^{2+}_{0.0001} \mid \text{M}$

If value of $E^\circ_{\text{Cell}}$ is 4 volt (Given $\frac{RT}{F} \ln 10 = 0.06$)

Select the correct set of answer:

Find out time period of $1^{st}$ order reaction. When reaction complete 2/$3^{rd}$. If the value of rate constant is 4.3×10⁻⁴

At what temperature does the rate become double than at 300 K? Given:

$\ln k = 10 - \frac{69(\text{kJ})}{\text{RT}}$

The vapour pressure of pure $\text{CHCl}_3$ and $\text{CH}_2\text{Cl}_2$ are 200 and 41.5 atm respectively. The weight of $\text{CHCl}_3$ and $\text{CH}_2\text{Cl}_2$ are resepectively 11.9 g and 17 gm. The vapour pressure of solution will be

Which will release $\text{NH}_3$ on Reaction with $\text{NaOH}$

When $\text{Ag}^+$ reacts with excess of sodium-thio sulphate then the obtained species having charge & geometry respectively will be?

Vapour pressure of $\text{CCl}_4$, at 25°C is 143 mm Hg. 0.5 g of a non-volatile solute (mol. wt. 65) is dissolved in 100 mL of $\text{CCl}_4$, Find the vapour pressure of the solution. ($\text{Density of CCl}_4, = 1.58\text{ g/cm}^3$)

Which of the following complexes has maximum CFSE?

For the reaction : $\text{A} + 2\text{B} \rightarrow \text{C} + \text{D}$, the expression of rate of reaction will

The Hybridisation and magnetic behavior of complex $\left[\text{Ni(CO)}_4\right]$ is :

In Fe(CO)₅ and Cr(CO)₆, how many CO ligands can be replaced by NO?

Calculate Molarity of a 63% w/w $\text{HNO}_3$ solution if density is $5.4\text{ g/mL}$:

For a first order reaction, a plot of $\log(a - x)$ against time is a straight line with negative slope equal to

Correct increasing order for the wavelength of absorption in the visible region for the complexes of $\text{Co}^{3+}$ is:

The conductivity of a 0.05 M solution of a weak monobasic acid is 10⁻³ S cm⁻¹. If λᵐ∞ for weak acid is 500 S cm² mol⁻¹, calculate Kₐ of weak monobasic acid:

$\text{C} + \text{O}_2(\text{g}) \rightarrow \text{CO}_2 \dots\dots(\text{i}); \quad \Delta\text{H} = -393 \text{ kJmol}^{-1}$

$\text{H}_2 + \frac{1}{2}\text{O}_2 \rightarrow \text{H}_2\text{O}, \dots\dots(\text{ii}); \quad \Delta\text{H} = -287.3 \text{ kJmol}^{-1}$

$2\text{CO}_2 + 3\text{H}_2\text{O} \rightarrow \text{C}_2\text{H}_5\text{OH} + 3\text{O}_2 \dots\dots(\text{iii}); \quad \Delta\text{H} = 1366.8 \text{ kJmol}^{-1}$

Find the standard enthalpy of formation of $\text{C}_2\text{H}_5\text{OH}(\text{l})$

Chloro compound of vanadium has only spin magnetic moment of 1.73 BM. This vanadium chloride has the formula:

In isolated system, find the condition for spontaneous reaction.

Assume that a particular amino acid has an isoelectric point of $6.0$. In a solution of $\text{pH } 1.0$, which of the following species will predominate?

Above compounds can be differentiated by following reagent:

What is X in the following reaction?

The decomposition of $\text{NH}_3$ on Pt surface is a zero order reaction. If the value of rate constant is $2 \times 10^{-4} \text{ mole liter}^{-1} \text{ sec}^{-1}$. The rate of appearance of $\text{N}_2$ and $\text{H}_2$ are respectively.

Assertion: Some salts are sparingly soluble at room temperature.

Reason: The entropy increases on dissolving the salts.

When $0.05 \text{ M}$ dimethyl amine is dissolved in $0.1 \text{ M NaOH}$ solution then the percentage dissociation of dimethyl amine is :

$(\text{K}_\text{b})_{(\text{CH}_3)_2\text{NH}} = 5 \times 10^{-4}$

Assertion : Reverse osmosis is used for desalination of sea water. Reason : Reverse osmosis occurs when a pressure larger than the osmotic pressure is applied to the solution.

Assertion : Ideal solutions obey Raoult's law. Reason : $\Delta\text{H}_{\text{mix}}$ and $\Delta\text{V}_{\text{mix}}$ for an ideal solution are less than zero.

In the primary structure of proteins, the amino acids are interconnected by-

Assertion : Potassium ferricyanide, $[\text{Fe}(\text{CN})_6]^{3-}$ is diamagnetic, while potassium ferrocyanide $[\text{Fe}(\text{CN})_6]^{4-}$ is paramagnetic.Reason : Oxidation state of $\text{Fe}$ in potassium ferricyanide is +2, but in potassium ferrocyanide its oxidation state is +3.

For the ions $\text{Zn}^{2+}$, $\text{Ni}^{2+}$ and $\text{Cr}^{3+}$ which among the following statements is correct? (Atomic number of Zn = 30, Ni = 28 and Cr = 24)

The IUPAC name for the complex $[\text{Co}(\text{NO}_2)(\text{NH}_3)_5]\text{Cl}_2$ is:

Assertion : Aliphatic tertiary amine can be distinguished from aromatic tertiary amines. Reason : Aliphatic tertiary amines react with nitrous acid to form insoluble nitrites.

Assertion : The penta-acetate of glucose does not react with hydroxylamine.

Reason : This is because free aldehyde group is not present in penta-acetate.