Science (English Medium) Class 12 - CBSE Question Bank Solutions

Which of the following ions has the electronic configuration 3d⁶?
(Atomic number: Mn = 25, Co = 27, Ni = 28)

Which of the following statements is not true about glucose?

A transition element X has an electronic configuration [Ar]4s²3d³. Predict its likely oxidation states.

Consider the following standard electrode potential values:

\[\ce{Sn^{2+}_{ (aq)} + 2e^- -> Sn_{(s)}}\]; E⁰ = −0.14 V

\[\ce{Fe^{3+}_{ (aq)} + e^- -> Fe^{2+}_{ (aq)}}\]; E⁰ = +0.77 V

What is the cell reaction and potential for the spontaneous reaction that occurs?

Write the number of unpaired electrons in Cr³⁺.
(Atomic number of Cr = 24)

Account for the following:

Copper has an exceptionally positive `"E"_("M"^(2+)//"M")^0` value.

Account for the following:

Eu²⁺ with electronic configuration [Xe]4f⁷6s² is a strong reducing agent.

The trend of which property is represented by the following graph?

Radioactive decay follows first-order kinetics. The initial amount of two radioactive elements X and Y is 1 gm each. What will be the ratio of X and Y after two days if their half-lives are 12 hours and 16 hours respectively?

In order to protect iron from corrosion, which one will you prefer as a sacrificial electrode, Ni or Zn? Why? (Given standard electrode potentials of Ni, Fe and Zn are -0.25 V, -0.44 V and -0.76 V respectively.)

The second ionization enthalpies of chromium and manganese are 1592 and 1509 kJ/mol respectively. Explain the lower value of Mn.

Give two similarities in the properties of Sc and Zn.

What is the oxidation state of chromium in chromate ion and dichromate ion?

Write the ionic equation for reaction of KI with acidified KMnO₄.

Draw the structures of the given compound - 3-Bromo-4-phenylpentanoic acid

Draw the structures of the following compound.

3-Bromo-4-phenylpentanoic acid

Write the structure of the following compound.

Di-sec. butyl ketone

Draw the structure of the following compound.

3-Bromo-4-phenyl pentanoic acid

Draw the structures of the following compound

3-Bromo-4-phenyl pentanoic acid.

Draw the structure of the following compound.

3-Bromo-4-phenylpentanoic acid