List of practice Questions

A steel rod 100 cm long is clamped at its middle. The fundamental frequency of longitudinal vibrations of the rod are given to be 2.53 kHz. What is the speed of sound in steel?

One end of a U-tube containing mercury is connected to a suction pump and the other end to atmosphere. A small pressure difference is maintained between the two columns. Show that, when the suction pump is removed, the column of mercury in the U-tube executes simple harmonic motion.

The acceleration due to gravity on the surface of moon is 1.7 ms-2.What is the time period of a simple pendulum on the surface of moon if its time period on the surface of earth is 3.5 s? (g on the surface of earth is 9.8 ms-2

Which important property did Mendeleev use to classify the elements in his periodic table and did he stick to that? 
What is the basic difference in approach between the Mendeleev's Periodic Law and the Modern Periodic Law?
On the basis of quantum numbers, justify that the sixth period of the periodic table should have 32 elements.
In terms of period and group where would you locate the element with Z =114?
Write the atomic number of the element present in the third period and seventeenth group of the periodic table.
Which element do you think would have been named by
(i) Lawrence Berkeley Laboratory
(ii) Seaborg's group?
Why do elements in the same group have similar physical and chemical properties?
What does atomic radius and ionic radius really mean to you?
How does atomic radius vary in a period and in a group? How do you explain the variation?
What do you understand by isoelectronic species? Name a species that will be isoelectronic with each of the following atoms or ions. 
  1. F- 
  2. Ar 
  3. Mg2+ 
  4. Rb+
Consider the following species: N3- , O2-, F-, Na+, Mg2+ and Al3+ 
  1. What is common in them? 
  2. Arrange them in the order of increasing ionic radii.
Explain why cations are smaller and anions larger in radii than their parent atoms?
Anything that influences the valence electrons will affect the chemistry of the element. Which one of the following factors does not affect the valence shell?

The size of isoelectronic species - F-, Ne and Na+ is affected by

What are the various factors due to which the ionization enthalpy of the main group elements tends to decrease down a group?
The first ionization enthalpy values (in kJmol-1 ) of group 13 elements are :
BAlGaInTl
801577579558589
How would you explain this deviation from the general trend?
Which of the following pairs of elements would have a more negative electron gain enthalpy? 
  1. O or F 
  2. F or Cl
Dinitrogen and dihydrogen react with each other to produce ammonia according to the following chemical equation: \(N_2 (g) + H_2 (g) → 2NH_3 (g)\)
  1. Calculate the mass of ammonia produced if 2.00 × 103 g dinitrogen reacts with 1.00 × 103 g of dihydrogen.
  2. Will any of the two reactants remain unreacted?
  3. If yes, which one and what would be its mass?
How are 0.50 mol Na2CO3 and 0.50 M Na2CO3 different?
If 10 volumes of dihydrogen gas reacts with five volumes of dioxygen gas, how many volumes of water vapour would be produced?
Name three groups of plants that bear archegonia. Briefly describe the life cycle of any one of them.
(i) Calculate the number of electrons which will together weigh one gram.
(ii) Calculate the mass and charge of one mole of electrons.