English

Science (English Medium) Class 12 - CBSE Important Questions for Chemistry

Advertisements
Subjects
Topics
Subjects
Popular subjects
Topics
Advertisements
Advertisements
Chemistry
< prev  821 to 840 of 1313  next > 

Explain the observation, at the end of each period, there is a slight increase in the atomic radius of d-block elements.

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Electronic Configurations of the d-block Elements

What is the effect of pH on dichromate ion solution?

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Important Compounds of Transition Elements

Give reason for the following statement:

[Ti(H2O)]3+ is coloured while [Sc(H2O)6]3+ is colourless.

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Physical Properties of the Transition Elements (d-block)

The oxidation state of Fe in [Fe(CO)5] is ______.

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Physical Properties of the Transition Elements (d-block)

Assertion (A): Transition metals have high enthalpy of atomisation.

Reason (R): Greater number of unpaired electrons in transition metals results in weak metallic bonding.

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Physical Properties of the Transition Elements (d-block)

Which one among the following metals of the 3d series has the lowest melting point?

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Physical Properties of the Transition Elements (d-block)

Which of the following transition metals shows +1 and +2 oxidation states?

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Physical Properties of the Transition Elements (d-block)

Assertion (A): Transition metals show their highest oxidation state with oxygen.

Reason (R): The ability of oxygen to form multiple bonds to metals.

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Physical Properties of the Transition Elements (d-block)

In the two tetrahedral structures of dichromate ion, ______.

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Important Compounds of Transition Elements

Complete the following reaction and justify that it is a disproportionation reaction:

\[\ce{3MnO^{2-}4 + 4H^+ -> \underline{}\underline{}\underline{}\underline{} + \underline{}\underline{}\underline{}\underline{} + 2H2O}\]

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Physical Properties of the Transition Elements (d-block)

The given graph shows the trends in melting points of transition metals:

Explain the reason why Cr has the highest melting point and manganese (Mn) has a lower melting point.

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Physical Properties of the Transition Elements (d-block)

Consider the following standard electrode potential values:

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

\[\ce{MnO^{-4}_{ (aq)} + 8H^+ + 5e^- -> Mn^{2+}_{ (aq)} + 4H2O_{(l)}}\], E0 = +1.51 V

What is the cell potential for the redox reaction?

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Physical Properties of the Transition Elements (d-block)

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

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Physical Properties of the Transition Elements (d-block)

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

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Physical Properties of the Transition Elements (d-block)

Complete the reaction mentioning all the products formed:

\[\ce{2KMnO4 ->[\Delta]}\]

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Important Compounds of Transition Elements

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?

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Physical Properties of the Transition Elements (d-block)

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

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Physical Properties of the Transition Elements (d-block)

Complete the reaction mentioning all the products formed:

\[\ce{Cr2O^{2-}7 + 3H2S + 8H^+ ->}\]

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Important Compounds of Transition Elements

Account for the following:

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

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Physical Properties of the Transition Elements (d-block)

Account for the following:

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

Appears in 1 question paper
Chapter: [4] d-block and f-block Elements
Concept: Physical Properties of the Transition Elements (d-block)
< prev  821 to 840 of 1313  next > 
Advertisements
Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×