Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions for Chemistry

Which one of the following is a polysaccharide:

Starch, Maltose, Fructose, Glucose

Seeing the growing cases of diabetes and depression among young children, Mr Lugani, the principal of one reputed school, organised a seminar in which he invites parents and principals. They all resolved this issue by strictly banning junk food in schools and introducing healthy snacks and drinks like soup, lassi, milk etc. in school canteens. They also decided to make compulsory half an hour of daily physical activities for the students in the health survey in most of the school and discovered a tremendous improvement in the health of the students

After reading the above passage, answer the following questions:

(i) What are the values (at least two) displayed by Mr Lugani?

(ii) As a student, how can you spread awareness about this issue?

(iii) What are antidepressant drugs? Give an example.

(iv) Name the sweetening agent used in the preparation of sweets for a diabetic patient.

Account for the following : Solid PCl₅ is ionic in nature.

Write the equation involved in the acetylation of Salicylic acid.

Mr. Roy, the principal of one reputed school organized a seminar in which he invited parents and principals to discuss the serious issue of diabetes and depression in students. They all resolved this issue by strictly banning the junk food in schools and to introduce healthy snacks and drinks like soup, lassi, milk etc. in school canteens. They also decided to make compulsory half an hour physical activities for the students in the morning assembly daily. After six months, Mr. Roy conducted the health survey in most of the schools and discovered a tremendous improvement in the health of students.

After reading the above passage, answer the following :

(i) What are the values (at least two) displayed by Mr. Roy ?

(ii) As a student, how can you spread awareness about this issue ?

(iii) What are tranquillizers ? Give an example.

(iv) Why is use of aspartame limited to cold foods and drinks ?

How is ‘cast iron’ different from ‘pig iron’?

Write the chemical equations involved when aniline is treated with the following reagents:

CHCI₃ + KOH

A compound 'A' of molecular formula C₂H₃OCl undergoes a series of reactions as shown below. Write the structures of A, B, C and D in the following reactions :

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: CH₃CHO in the presence of dilute NaOH

Complete the following equations: Ag+PCl₅ →

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.