Advertisements
Advertisements
Question
Which of the following will not act as oxidising agents?
(i) \[\ce{CrO3}\]
(ii) \[\ce{MoO3}\]
(iii) \[\ce{WO3}\]
(iv) \[\ce{CrO^{2-}4}\]
Advertisements
Solution
(ii)\[\ce{MoO3}\]
(iii) \[\ce{WO3}\]
Explanation:
A compound act as oxidising agent when it’s central atom is reduced to its lower oxidation state. This occurs only when the lower oxidation state of metal is more stable than the higher oxidation states.
In metal \[\ce{WO3}\] and \[\ce{CrO4^{2-}}\], both W and Cr are stable in their higher oxidation state and won’t get reduced to their lower oxidation state. Therefore, will not act as oxidising agents.
APPEARS IN
RELATED QUESTIONS
Complete the following chemical equations:
`(i) Cr_2O_7^(2-)+6Fe^(2+)+14H^+ ->`
`(ii) 2CrO_4^(2-)+2H^+ ->`
`(iii) 2MnO_4^-+5C_2O_4^(2-)+16H^+ ->`
Give reasons:
Transition metals show variable oxidation states.
Account for the following:
E° value for the Mn3+/Mn2+ couple is much more positive than that for Cr3+/Cr2+.
How is the variability in oxidation states of transition metals different from that of the non-transition metals? Illustrate with examples.
How would you account for the following:
Cobalt (II) is stable in aqueous solutions, but in the presence of complexing reagents, it is easily oxidised.
What is meant by ‘disproportionation’?
Why do transition metal ions possess a great tendency to form complexes?
Account for the following :
Ti4+ is colourless whereas V4+ is coloured in an aqueous solutions.
Explain why transition elements form alloys.
Which among the following transition metal has the lowest melting point?
Which of the following statements is not correct?
Assertion (A): Cu cannot liberate hydrogen from acids.
Reason (R): Because it has positive electrode potential.
Assertion: The highest oxidation state of osmium is +8.
Reason: Osmium is a 5d-block element.
Answer the following question:
Which element of the first transition series has highest second ionisation enthalpy?
Fill in the blanks by choosing the appropriate word(s) from those given in the brackets:
(activation energy, Threshold energy, increased, lowered, partially, full, d-d transition, Benzoic acid, benzaldehyde)
Only those transition metal ions will be coloured which have ______ filled d-orbitals facilitating ______.
The product of oxidation of I– with \[\ce{MnO^{-}4}\] in alkaline medium is:-
Which of the following characteristics of transition metals is associated with their catalytic activity?
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.
A transition element X has an electronic configuration [Ar]4s23d3. Predict its likely oxidation states.
Give two similarities in the properties of Sc and Zn.
