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

Pure benzene freezes at 5.45°C. A 0.374 m solution of tetrachloroethane in benzene freezes at 3.55°C. The Kf for benzene is:

A 5% solution (by mass) of cane sugar in water has a freezing point of 271 K and a freezing point of pure water is 273.15 K. The freezing point of a 5% solution (by mass) of glucose in water is:

0.01 M solution of KCl and BaCl₂ are prepared in water. The freezing point of KCl is found to be – 2°C. What is the freezing point of BaCl₂ to be completely ionised?

The freezing point of equimolal aqueous solution will be highest for ____________.

Which of the following 0.10 m aqueous solutions will have the lowest freezing point?

A solution containing 1.8 g of a compound (empirical formula CH₂O) in 40 g of water is observed to freeze at –0.465° C. The molecular formula of the compound is (K_f of water = 1.86 kg K mol^–1):

Which observation(s) reflect(s) colligative properties?

(i) A 0.5 m NaBr solution has a higher vapour pressure than a 0.5 m BaCl₂ solution at the same temperature.

(ii) Pure water freezes at a higher temperature than pure methanol.

(iii) A 0.1 m NaOH solution freezes at a lower temperature than pure water.

The ether

when treated with HI produces:

In comparison to a 0.01 m solution of glucose, the depression in freezing point of a 0.01 m MgCl₂ solution is ______.

Which of the following statement is false?

If molality of dilute solution is doubled, the value of molal depression constant (K_f) will be ______.

Which has the highest freezing point?

Ozone is a/an _______ molecule and the two O-O bond lengths in ozone are (i) _______-and (ii) _________.

Given below are two statements labelled as Assertion (A) and Reason (R).

Assertion (A): Cryoscopic constant depends on nature of solvent.

Reason (R): Cryoscopic constant is a universal constant.

Select the most appropriate answer from the options given below:

Which of the following statements is false?

How does sprinkling of salt help in clearing the snow covered roads in hilly areas? Explain the phenomenon involved in the process.

Assertion: When NaCl is added to water a depression in freezing point is observed.

Reason: The lowering of vapour pressure of a solution causes depression in the freezing point.

What advantage do the fuel cells have over primary and secondary batteries?

Match the items of Column I and Column II.

Which of the following interface cannot be obtained?