List of practice Questions

Write the general outer electronic configuration of \(s-, p-, d-\) and \(f-\) block elements.
The first\((\triangle_ iH_1)\) and the second \((\triangle_iH)\) ionization enthalpies (in \(kJ\; mol ^{-1}\) ) and the \((\triangle_{eg}H)\) electron gain enthalpy (in \(kJ \;mol^{ -1}\) ) of a few elements are given below: 
Elements                       \(\triangle_iH\)                \(\triangle_iH\)                \(\triangle_{eg}H\) 
   I                                    520                   7300                    -60 
  II                                    419                   3051                    -48 
  III                                  1681                  3374                    -328  
  IV                                  1008                 1846                    -295 
  V                                   2372                  5251                   +48 
  VI                                  738                    1451                    -40
Which of the above elements is likely to be : 
  1. the least reactive element.
  2. the most reactive metal.
  3. the most reactive non-metal.
Assign the position of the element having outer electronic configuration
  1. \(ns^ 2 np^ 4\) for \(n\) = \(3\) 
  2. \((n - 1)d^ 2 \;ns^ 2\) for \(n\) =\( 4\), and 
  3. \((n - 2) f ^7 (n - 1)d ^1 ns^ 2\) for \(n\) = \(6\), in the periodic table.
Which one of the following statements is incorrect in relation to ionization enthalpy?
What is the basic theme of organisation in the periodic table?
Which important property did Mendeleev use to classify the elements in his periodic table and did he stick to that? 
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.
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+
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?
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
How would you explain the fact that the first ionization enthalpy of sodium is lower than that of magnesium but its second ionization enthalpy is higher than that of magnesium?
Among the second period elements the actual ionization enthalpies are in the order 
Li < B < Be < C < O < N < F < Ne. 
Explain why 
  1. Be has higher ΔiH than B
  2. O has lower ΔiH than N and F?
Energy of an electron in the ground state of the hydrogen atom is -2.18 x 10-18  J. Calculate the ionization enthalpy of atomic hydrogen in terms of J mol-1  .
What is the significance of the terms - 'isolated gaseous atom' and 'ground state' while defining the ionization enthalpy and electron gain enthalpy?
Hint: Requirements for comparison purposes.
Would you expect the second electron gain enthalpy of O as positive, more negative or less negative than the first? Justify your answer.
What is the basic difference between the terms electron gain enthalpy and electronegativity?
How would you react to the statement that the electronegativity of N on Pauling scale is 3.0 in all the nitrogen compounds?