List of top Questions asked in UP Board XII

What is the effect of catalyst on the rate of reaction? A first-order reaction is 40\% completed in 50 minutes. Calculate the time taken for 80\% completion of the reaction. (Given: \(\log 2 = 0.3010\) and \(\log 6 = 0.7782\))
Write a short note on denaturation of proteins.
Explain the difference between molecularity and order of reaction. Show that the time taken to complete three-fourth of the first-order reaction is doubled to its half-life.
Define molal depression constant. Calculate the freezing point of the aqueous solution containing 25 g of ethylene glycol (C\(_2\)H\(_6\)O\(_2\)) in 300 g of water. The value of molal depression constant for water is 1.86 K kg mol\(^{-1}\) and freezing point of water is 273.15 K.
What is osmotic pressure? Explain the difference between osmosis and diffusion with an example.
Describe the mechanism of bimolecular nucleophilic substitution reactions (\( S_N2 \)) in haloalkanes.
Explain the acidic nature of phenol.
Discuss the method of preparation of potassium dichromate from chromite ore and write the structural formula of dichromate ion.
2.82 g of glucose (molar mass = 180 g mol\(^{-1}\)) is dissolved in 30 g of water. Calculate the molality of the solution.
In which of the following compounds, oxidation number of Mn is +6?
Which of the following gives isocyanide test?
Which of the following ligands can act as an ambidentate ligand?
In nucleic acids, the nucleotides are linked together by
The colligative property is
Effect of temperature on rate of reaction and calculation of time for 80\% completion.
Explain the difference between aldehydes and ketones by Fehling solution and Schiff reagent.
Explain the mechanism of dehydration of ethanol.
Explain ionisation isomerism and linkage isomerism in coordination compounds with example.
After eliminating salt bridge of any Galvanic cell, voltage of the cell:
Four alternatives are given in each part of this question. Write the correct alternative in your answer-book. Fe is:
Write the chemical equations for the preparation of 1-iodobutane from the following: 1-butanol
How does the acidified \( KMnO_4 \) solution react with ferrous sulphate, \( SO_2 \), oxalic acid, and sodium thiosulphate?
Calculate the e.m.f. of the following cell writing the cell reaction: \[ \text{Cu} | \text{Cu}^{2+}(1M) || \text{Ag}^+(1M) | \text{Ag} \] Given: \[ E^0_{\text{Cu}^{2+}/\text{Cu}} = +0.34 \text{ volt}, \quad E^0_{\text{Ag}^+/\text{Ag}} = +0.80 \text{ volt} \]
Write the units of velocity and velocity constant for zero order reaction.
For a first-order reaction, prove that the time taken in completion of 3/4 part of the reaction is two times that of its half-life period.