PUC Science 2nd PUC Class 12 - Karnataka Board PUC Question Bank Solutions for Chemistry

Write the structures of the main products when acetone (CH₃ − CO − CH₃) reacts with the following reagent :

H₂N − NHCONH₂/H⁺

Write the mechanism of the following reaction :

On the occasion of World Health Day, Dr. Satpal organized a ‘health camp’ for the poor farmers living in a nearby village. After check-up, he was shocked to see that most of the farmers suffered from cancer due to regular exposure to pesticides and many were diabetic. They distributed free medicines to them. Dr. Satpal immediately reported the matter to the
National Human Rights Commission (NHRC). On the suggestions of NHRC, the government decided to provide medical care, financial assistance, setting up of super-speciality hospitals for treatment and prevention of the deadly disease in the affected villages all over India.

(i) Write the values shown by

(a) Dr. Satpal

(b) NHRC

(ii) What type of analgesics are chiefly used for the relief of pains of terminal cancer ?

(iii) Give an example of artificial sweetener that could have been recommended to diabetic patients

Write the products formed when CH₃CHO reacts with the following reagents : HCN

Write the products formed when CH₃CHO reacts with the following reagents : H₂N – OH

What are the products of hydrolysis of maltose?

Complete the following equations: Ag+PCl₅ →

Define the following term:

Invert sugar

Define the following terms:

Oligosaccharides

The conductivity of 0.20 M solution of KCl at 298 K is 0.0248 S cm⁻¹. Calculate its molar conductivity.

The resistance of a conductivity cell containing 0.001 M KCl solution at 298 K is 1500 Ω. What is the cell constant if the conductivity of 0.001 M KCl solution at 298 K is 0.146 × 10⁻³ S cm⁻¹.

Define conductivity for the solution of an electrolyte.

What is the role of desorption in the process of catalysis?

The reaction,

Cr₂O₃ + 2Al → Al₂O₃ + 2Cr

 (ΔG^θ = -421kJ) is thermodynamically feasible as is apparent from the Gibbs energy value.  Why does it not take place at room temperature?

Is it true that under certain conditions, Mg can reduce SiO₂ and Si can reduce MgO? What are those conditions?

Why is the extraction of copper from pyrites more difficult than that from its oxide ore through reduction?

Write down the reactions taking place in different zones in the blast furnace during the extraction of iron.

Write chemical reactions taking place in the extraction of zinc from zinc blende.

State the role of silica in the metallurgy of copper.

The choice of a reducing agent in a particular case depends on thermodynamic factor. How far do you agree with this statement? Support your opinion with two examples.