Home
Class 12
CHEMISTRY
Explain the following observations. a....

Explain the following observations.
a. Sun looks red at the time of sunset.
b. Rate of physical adsorption decreases with rise in temperature.

Text Solution

Verified by Experts

The correct Answer is:
At the time of settings, the sum is at the horizon. The light emitted by the sun has to travel a longer distance through the atmosphere. As a result, blue part of the light is scattered away by the dust particles in the atmosphere. Hence, the red part is visible.
Promotional Banner

Similar Questions

Explore conceptually related problems

Which of the following does not decrease with rise in temperature ?

Following is the variation of physical adsorption with temperature.

Which of the following statements is not true? a. Both physisorption and chemisorption are exothermic. b. Physisorption occurs with increase of free energy. c. Physisorption requires low activation energy but chemisorption requires high activation energy. d. The magnitude of chemisorption increases and that of physisorption decreases with rise in temperature.

Explain graphically how the rate of a reaction changes with every 10^@ C rise in temperature.

Derive the variation of x/m versus temperature for physical adsorption process. Explain the nature of the curve.

Comment on the following statements. (a) Evaporation produces cooling. (b) Rate of evaporation of an aqueous solution decreases with increase in humidity . (c) Sponge though compressible is a solid.

Explain the following observations : (i) Nitrogen is much less reactive than phosphorus. (ii) Despite having greater polarity, hydrogen fluoride boils at a lower temperature than water.

Observe the given adsorption isotherm carefully and choose the correct option (i) These curves indicates that at a fixed temperature, there is a decrease in physical adsorption with increase in pressure. (ii) These curves always seem to approach saturation at high pressure. x/m=k*p^(1//n) (n gt 1) is generally represented by this isotherm. (iv) These curves indicate that at a fixed pressure, there is a decrease in physcial adsorption with increase in temperature .

(a) Explain the following terms : (i) Order of a reaction (ii) Molecularity of a reaction (b) The rate of a reaction increases four times when the temperature changes from 300 K to 320 K. Calculate the energy of activation of the reaction, assuming that it does not change with temperature. (R = 8.314 J K^(-1) mol^(-1))

Explain the following observations: (a) Azide ion (N_(3)) react with 2- bromopentane thousand times faster than with neopentyl bromide in a S_(N)2 reaction through former is a secondary halide while latter is primary. (b) What will happen to the stereochemistry of product of the following reaction: (c) What will happens to the rate if the concentration of alkyl bromide in (b) is doubled? (d) Wha will happen to the rate if the concentration of azide ion in (b) is doubled? (e) How the sign of optical rotation of reactant and product are related in (b) (f) When allowed to stand in dilute H_(2)SO_(4) laevo-rotatory 2-butanol slowly loss optical activity.