AIIMS Chemistry Class 12 Questions

The complete reaction is shown below. In the above reaction, the reactant undergoes 1,4 Michael addition first then the formed intermediate undergoes reduction in the presence of NaBH₄ to form the desired product.

Correct order of electrophilic substitution reaction is:

The Sₙ2 reaction is a single step reaction and given by less bulky groups. The ease of carbocation towards Sₙ2 reaction is shown below.

The complete reaction is shown below. The desired product of the given reaction is α,β–unsaturated carbonyl compound.

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:

The reaction of glyceraldehyde with Br₂/H₂O.

When phenol reacts with aniline in the presence of diazonium salt (C₆H₅N₂⁺Cl⁻) and a base (KOH), p-hydroxyazobenzene is formed as a major product.

Assertion : d⁵ configuration is more stable than d⁴ Reason : d⁵ has more exchange energy as compared to d⁴ because 10 & 6 exchanges are possible in d⁵ & d⁴ respectively.

Correct order for reaction with alcoholic KOH

When¹⁻chloro^{-3}-methoxybenzene reacts with nitric acid and sulphuric acid, it forms²⁻chloro^{-4}-methoxy^{-1}-nitrobenzene. The nitro group gets attached to para-position due to steric hindrance at ortho position. The reaction is shown below.

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

The +I effect shown by methyl group increases the basic strength of the following compound.

The reaction is

Which of the following complex is optically inactive (1) [RhCl(CO)(PPh₃)(NH₃)] (2) [Fe(C₂O₄)₃]³⁻ (3) [Fe(en)₂Cl₂] (4) [Pd(en)₂Cl₂]

The complete reaction is shown below. From the above reaction, it is clear that the amino group is o-p-directing in nature.

Assertion: Two sugar units joined by 1,2-glycosidic bond in sucralose. Reason: It contains 1 C-glucose and 2 C -fructose glycosidic bond

A(g) → 2B(g) + C(g) Initial: P₀ 0 0 P₀ - P 2P P Pₜ = P₀ - P + 2P + P = P₀ + 2P Therefore, P = (Pₜ + P₀) / 2 Apply the expression shown below to calculate rate constant. k = (2.303 / t) log [P₀ / (P₀ - P)] Substitute the value of P in above equation.

Correct increasing order for the wavelength of absorption in the visible region for the complexes of Co³⁺ is: (1) [Co(CN)₆]³⁻, [Co(NH₃)₆]³⁺, [Co(NH₃)₅(H₂O)]³⁺[Co(NH₃)₅Cl]²⁺ (2) [Co(CN)₆]³⁻, [Co(NH₃)₅(H₂O)]³⁺[Co(NH₃)₅Cl]²⁺ [Co(NH₃)₆]³⁺, (3) [Co(NH₃)₅]²⁺, [Co(CN)₆]³⁻, [Co(NH₃)₅(H₂O)]³⁺[Co(NH₃)₅Cl]²⁺ (4) [Co(NH₃)₅Cl]²⁺, [Co(NH₃)₅(H₂O)]³⁺, [Co(NH₃)₄]³⁺, [Co(CN)₆]³⁻

Higher the hydration energy of a compound, higher will be its solubility. Be²⁺ has highest hydration energy, therefore, its solubility is maximum.

The reactant, NH₂−CH₂−CH₂−OH possesses two nucleophilic groups −OH and −NH₂, in which is −NH₂ is stronger. So, −NH₂ react at the region at which stable carbocation gets formed. The complete reaction is shown below.

The complete reaction is shown below.

In glucose, there is absence of free aldehyde group and it forms cyclic hemiacetal form as shown below.

In coordination complex [Co(C₂O₄)₃]³⁻, Co³⁺ acts as a central metal ion. Co³⁺ shows d²sp³ hybridization hence all the electrons are paired and diamagnetic in nature. Thus, it is a low spin complex.

If Boiling point of water is 100°C. How much gram of NaCl is added in 500 g of water to increase its boiling point of water by approx 1°C. (K_b)H₂O = 0.52 K kg/mole.

Phenol reacts with CH₃I in presence of NaOH to form methoxybenzene as shown below: In the presence of NaOH, phenol forms phenoxide ion which is a better nucleophile than phenol. So, both assertion and reason are true and reason is the correct explanation of assertion.

Starch is a polysaccharide and on reaction with iodine it will give a blue-black color.

The structures of all the oxo-acids of phosphorus are shown below:

Assertion: Tert. Butyl amine can be formed by Gabriel phthalimide synthesis Reason: It follow N S 1 mechanism

At 298 K temperature, A hydrogen gas electrode is made by dipping platinum wire in a solution of HCl of pH = 10 and by passing hydrogen gas around the platinum were at one atm pressure. The potential of electrode would be?

Which of the following does not give ppt with CrO₄²⁻

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

The rate constant can be calculated by using Arrhenius equation as shown below: k = Ae⁻ᴱᵃ/ᴿᵀ = 4 × 10¹⁰ × e⁻⁽⁻⁵⁴.⁷×¹⁰⁰⁰⁾/⁽⁸.³¹⁴×⁸⁰⁰⁾ = 4 × 10¹⁰ × e⁻⁸.²²⁴ = 4 × 10¹⁰ × 2.68 × 10⁻⁴ = 10.7 × 10⁶

$\text{C}_7\text{H}_{10}\text{O}$ 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

H₂O₂ is obtained by the reaction of BaO₂ with sulfuric acid. BaO₂·8H₂O(s) + H₂SO₄(aq) → BaSO₄ + H₂O₂ + H₂O Therefore option (1) is correct.

Calculate emf of cell at 25°C Cell notation: M|M²⁺ 0.01 || M²⁺ 0.0001|M If value of E⁰ₓₑₗₗ is 4 volt (Given RT/F ln 10 = 0.06)

The decomposition of NH₃ on Pt surface is a zero order reaction. If the value of rate constant is 2 x 10⁻⁴ mole liter⁻¹ sec⁻¹. The rate of appearance of N₂ and H₂ are respectively:

Assertion: Some salts are sparingly soluble at room temperature. Reason: The entropy increases on dissolving the salts.

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

Select the correct set of answer:

lnk = 10 - 69(KJ)/RT ……(i) k = Ae^(-Ea/RT) ln k = ln A - Ea/RT ……(ii) Comparison of equation (i) and(ii) Ea is 69. The rate constants in Arrhenius equation at two different temperatures are expressed as stated below.

The vapour pressure of pure CHCl₃ and CH₂Cl₂ are 200 and 41.5 atm respectively. The weight of CHCl₃ and CH₂Cl₂ are respectively 11.9 g and 17 gm. The molar mass of CHCl₃ is 119.5 g/mol and the molar mass of CH₂Cl₂ is 85 g/mol. The number of moles of CHCl₃ is calculated below.

What is the activation energy (kJ/mol) for a reaction if its rate constant doubles when the temperature is raised from 300 K to 400 K? (R = 8.314 J mol⁻¹ K⁻¹)

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

The mole fraction of solute is equal to the relative lowering of vapour pressure, x₂ = (P₀ - Pₛ) / P₀. Substitute the given values in the above equation.

The reaction of Ag⁺ with excess of sodium-thiosulphate is given below. Ag⁺ + Na₂S₂O₃ → [Ag(S₂O₃)₂]³⁻. This complex possesses^{-3} charge. The coordination number for Ag is 2 which correspond to sp hybridization and linear geometry.

Which of the following complexes has maximum CFSE?

NH₃ reacts with bleaching powder to give:

The inert gas participate in chemical reaction is xenon because the size of xenon is very large which decreases its ionization potential.

Which give colored carbonate precipitate?