CUET · CHEMISTRY · PYQ PAPER 2025
Read the passage carefully and answer the questions
The transition metals and their compounds are known for their catalytic activity. This activity is ascribed to their ability to adopt multiple oxidation states and to form complexes. Vanadium(V) oxide (in Contact Process), finely divided iron, and nickel (in Catalytic Hydrogenation) are some of the examples. Catalysts at a solid surface involve the formation of bonds between reactant molecules and atoms of the surface of the catalyst (first row transition metals utilise 3d and 4s electrons for bonding). This has the effect of increasing the concentration of the reactants at the catalyst surface and also weakening of the bonds in the reacting molecules (the activation energy is lowering). Also because the transition metal ions can change their oxidation states, they become more effective as catalysts.
In the Wacker process the oxidation of ethene to ethanal is catalysed by _______
- A \(\ TiCl_4\)
- B \(\ PdCl_2\)
- C \(\ MnO_2\)
- D \(\ KMnO_4\)
Answer & Solution
Correct Answer
(B) \(\ PdCl_2\)
Step-by-step Solution
Detailed explanation
\(PdCl_2\)
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from CHEMISTRY
- The aqueous solutions of the following salts were electrolyzed for 30 min with a current of 20 amp. Arrange the
following in the increasing order of the amount of metal deposited at the cathode.
(A) \(\mathrm{WCl}_6\)
(B) \(\mathrm{ZnSO}_4\)
(C) \(\mathrm{HfCl}_4\)
(D) \(\mathrm{AgNO}_3\)
(Atomic mass of: W =184 u, Zn = 65 u, Hf = 178 u and Ag = 108u)
Choose the correct answer from the options given below:CUET 2025 Medium - For the first order reaction :
(A) The degree of dissociation is equal to \((1 – e^{-kt})\)
(B) A plot of reciprocal concentration of the reactant v/s time gives a straight line
(C) The time taken for the completion of 75\% reaction is thrice the half life of the reaction
(D) 1st order reaction never completes
Choose the correct answer from the options given below :CUET 2023 Easy - The gas evolved when methylamine reacts with nitrous acid isCUET 2025 Medium
- Least basic compound among the following would be:CUET 2023 Medium
- Milk sugar, a disaccharide, is composed ofCUET 2025 Easy
- Which transition metal group is known as coinage metals?CUET 2025 Hard
More PYQs from CUET
- Applying the Kirchhoff's rule to the loop (a) ABCA and (b) BCDEB, two correct equations are given

(A) \(8-4 I_2-2\left(I_2+I_3\right)-I_1=0\)
(B) \(4-2\left(I_2+I_3\right)-4\left(I_2+I_3-I_1\right)=0\)
(C) \(4+2\left(I_2-I_3\right)-4\left(I_2+I_3-I_1\right)=0\)
(D) \(8+4 I_2+2\left(I_2-I_3\right)-I_1=0\)
Choose the correct answer from the options given below:CUET 2025 Medium - Match List-I with List-II
Choose the correct answer from the options given below:List-I (Reaction) List-II (Type of reaction) (A) Hydrolysis of Ethyl Chloride (I) Substitution reaction (B) 2-Propanol is treated with Conc. Sulphuric acid (II) Addition reaction (C) Reaction of HCN with Acetone (III) Degradation reaction (D) Treatment of acetamide with NaOH and Br2 (IV) Elimination reaction CUET 2025 Medium - Consider the following hypothesis test.
\(H _0: \mu \leq 12\)
\(H _a: \mu>12\)
If a sample of 25 is taken with sample mean 15 and a sample standard deviation of 6, then the value of t-test statistic is:CUET 2025 Easy - The derivative of \(\cos ^{-1}\left(\frac{\sin x+\cos x}{\sqrt{2}}\right),-\frac{\pi}{4} < x < \frac{\pi}{4}\) with respect to \(x\) is :CUET 2023 Hard
- A proton and an alpha particle moving with equal kinetic energies enter perpendicularly into a magnetic field. If \( r_p \) and \( r_\alpha \) are the respective radii of their circular paths, what will be the ratio \( \frac{r_p}{r_\alpha} \)?CUET 2025 Easy
- Read the following passage carefully and answer the given questions.
Insulin consists of two short polypeptide chains- chain A and chain B, that are linked together by disulphide bridges. Some strains of Bacillus thuringiensis produce proteins that kill certain insects such as lepidopterans, coleopterans and dipterans. Bt toxin protein is converted into an active form of toxin due to the alkaline pH of the gut which solubilise the crystals. Transgenic animals that produce useful biological products can be created by the introduction of the portion of DNA (or genes) which codes for a particular product such as human protein (alpha-1-antitrypsin) used to treat emphysema. Plants, bacteria, fungi and animals whose genes have been altered by manipulation are called Genetically Modified Organisms (GMO). GM plants have been useful in many ways. Genetic modification has: (i) made crops more tolerant to abiotic stresses. (ii) reduced reliance on chemical pesticides (pest-resistant crops). (iii) helped to reduce post harvest losses. (iv) increased efficiency of mineral usage by plants (this prevents early exhaustion of fertility of soil). (v) enhanced nutritional value of food.
Which one of the following species is not killed by insecticidal protein produced by Bacillus thuringiensis?CUET 2025 Easy