Science (English Medium) Class 11 - CBSE Question Bank Solutions for Chemistry

The work function for caesium atom is 1.9 eV. Calculate

1. the threshold wavelength and
2. 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.

The ejection of the photoelectron from the silver metal in the photoelectric effect experiment can be stopped by applying the voltage of 0.35 V when the radiation 256.7 nm is used. Calculate the work function for silver metal.

What will be the pressure exerted by a mixture of 3.2 g of methane and 4.4 g of carbon dioxide contained in a 9 dm³ flask at 27 °C ?

A mixture of dihydrogen and dioxygen at one bar pressure contains 20% by weight of dihydrogen. Calculate the partial pressure of dihydrogen.

Draw the resonance structure for the following compound. Show the electron shift using curved-arrow notation.

C₆H₅OH 

Draw the resonance structure for the following compound. Show the electron shift using curved-arrow notation.

C₆H₅NO₂ 

Draw the resonance structure for the following compound. Show the electron shift using curved-arrow notation.

CH₃CH = CHCHO

Draw the resonance structure for the following compound. Show the electron shift using curved-arrow notation.

C₆H₅ – CHO

Draw the resonance structure for the following compound. Show the electron shift using curved-arrow notation.

\[\ce{C6H5 - \overset{+}{C}H2}\]

Draw the resonance structure for the following compound. Show the electron shift using curved-arrow notation.

\[\ce{CH3CH = CH\overset{+}{C}H2}\]

If travelling at same speeds, which of the following matter waves have the shortest wavelength?

Which of the following will not show deflection from the path on passing through an electric field?

A hypothetical electromagnetic wave is shown in Figure. Find out the wavelength of the radiation.

What is photoelectric effect? State the result of photoelectric effect experiment that could not be explained on the basis of laws of classical physics. Explain this effect on the basis of quantum theory of electromagnetic radiations.

Which of the following have no unit?

(i) Electronegativity

(ii) Electron gain enthalpy

(iii) Ionisation enthalpy

(iv) Metallic character

Explain the following:

Electronegativity of elements increase on moving from left to right in the periodic table.

The pressure of a 1:4 mixture of dihydrogen and dioxygen enclosed in a vessel is one atmosphere. What would be the partial pressure of dioxygen?

The enthalpies of elements in their standard states are taken as zero. The enthalpy of formation of a compound ______.

Standard molar enthalpy of formation, ∆_fH^Θ is just a special case of enthalpy of reaction, ∆_rH^Θ. Is the ∆_rH^Θ for the following reaction same as ∆_fH^Θ? Give reason for your answer.

\[\ce{CaO(s) + CO2(g) -> CaCO3(s); ∆_fH^Θ = - 178.3 kJ mol^{-1}}\]

The enthalpy of reaction for the reaction: \[\ce{2H2 (g) + O2(g) -> 2H2O (l)}\] is ∆_rH^Θ = – 572 kJ mol^–1. What will be standard enthalpy of formation of \[\ce{H2O (l)}\]?