Class – XII – Solutions , Test Duration – 1:30 min
- Calculate the mass of ascorbic acid (Vitamin C, C6H8O6) to be dissolved in 75 g of acetic acid to
lower its melting point by 1.5°C. Kf = 3.9 K kg mol−1.
2.Calculate the osmotic pressure in pascals exerted by a solution prepared by dissolving 1.0 g of
polymer of molar mass 185,000 in 450 mL of water at 37°C.
- Give an example of solid solution in which the solute is a gas? Explain Henery’s law & is its significance?
4.What role does the molecular interaction play in a solution of alcohol and water?
5.Why do gases always tend to be less soluble in liquids as the temperature is raised?
- Calculate the depression in the freezing point of water when 10 g of CH3CH2CHClCOOH is added
to 250 g of water. Ka = 1.4 × 10−3, Kf = 1.86 K kg mol−1.
- Determine the osmotic pressure of a solution prepared by dissolving 25 mg of K2SO4 in 2 liter of water at
25° C, assuming that it is completely dissociated.
- Based on solute-solvent interactions, arrange the following in order of increasing solubility in
n-octane and explain – Cyclohexane, KCl, CH3OH, CH3CN. cont…..download from link given above .
Class – XI – Structure of Atoms – Duration 1:30 mint.
1 MARK QUESTION
- State the physical significance of psi (ψ)?
- Define K-Capture ?
- Which quantum numbers determine the magnetism of an atom?
- Why hockey ball does not seems to made wave?
- How many spectral lines will be obtained when electron jumps from 6th orbit
to ground state?
- 6. Why electron does not exist in nucleus ?
2 MARK QUESTION
- An e– has a speed of 500 ms– with an uncertainity of 0.02%. What is the
uncertainty in locating its position?
- Show that the circumference of the Bohr orbit for the hydrogen atom is an
integral multiple of the de Broglie wavelength associated with the electron
revolving around the orbit.
3 MARK QUESTION
- [a] Write Quantum number in case of Cr ( At. No. 24 ) –
- Highest energu Subshell .
- Outer most electron
[b] The kinetic energy of a sub-atomic particle is 4.55X10-25 J
Calculate the frequency of the particle wave.
- The work function for caesium atom is 1.9 eV. Calculate (a) the threshold
wavelength and (b) the threshold frequency of the radiation. If the caesium
element is irradiated with a wavelength 500 nm, calculate the kinetic energy
and the velocity of the ejected photoelectron.
cont……..download from the link given link.