Advertisements
Advertisements
Question
Write balanced chemical equations for the conversion of `CrO_4^(2-)` to `Cr_2O_7^(2-)` in acidic medium and `Cr_2O_7^(2-)` to `CrO_4^(2-)`
in basic medium.
Advertisements
Solution
`K_2Cr_2O_7 + 2KOH -> 2K_2CrO_4 + H_2O`
`2K_2CrO_4 + 2HCl -> K_2Cr_2O_7 + 2KCl + H_2O`
APPEARS IN
RELATED QUESTIONS
What are interstitial compounds?
Why do interstitial compounds have higher melting points than corresponding pure metals?
ln which pair highest oxidation states of transition metals are found:
Account for the following:
Mn shows the highest oxidation state of +7 with oxygen but with fluorine, it shows oxidation state of +4.
The elements of 3d transition series are given as: Sc Ti V Cr Mn Fe Co
Answer the following: Write the element which shows maximum number of oxidation states. Give reason.
The elements of 3d transition series are given as: Sc Ti V Cr Mn Fe Co
Answer the following: Which element is a strong oxidising agent in +3 oxidation state and why?
What are the transition elements? Write two characteristics of the transition elements.
Why are Mn2+ compounds more stable than Fe2+ towards oxidation to their +3 state?
For M2+/M and M3+/M2+ systems, the EΘ values for some metals are as follows:
| Cr2+/Cr | −0.9 V |
| Mn2+/Mn | −1.2 V |
| Fe2+/Fe | −0.4 V |
| Cr3/Cr2+ | −0.4 V |
| Mn3+/Mn2+ | +1.5 V |
| Fe3+/Fe2+ | +0.8 V |
Use this data to comment upon:
The stability of Fe3+ in acid solution as compared to that of Cr3+ or Mn3+.
What are inner transition elements?
Maximum magnetic moment is shown by ____________.
The magnetic moment is associated with its spin angular momentum and orbital angular momentum. Spin only magnetic moment value of \[\ce{Cr^{3+}}\] ion is ______.
Transition elements show magnetic moment due to spin and orbital motion of electrons. Which of the following metallic ions have almost same spin only magnetic moment?
(i) \[\ce{Co^{2+}}\]
(ii) \[\ce{Cr^{2+}}\]
(iii) \[\ce{Mn^{2+}}\]
(iv) \[\ce{Cr^{3+}}\]
Transition elements form binary compounds with halogens. Which of the following elements will form \[\ce{MF3}\] type compounds?
(i) \[\ce{Cr}\]
(ii) \[\ce{Co}\]
(iii) \[\ce{Cu}\]
(iv) \[\ce{Ni}\]
Transition elements show high melting points. Why?
The second and third rows of transition elements resemble each other much more than they resemble the first row. Explain why?
Mention any three processes where transition metals act as catalysts.
Account for the following:
In case of transition elements, ions of the same charge in a given series show progressive decrease in radius with increasing atomic number.
Catalytic hydrogenation of benzene gives
Sodium this sulphate is used in photography because of its:-
Give reasons for the following statement:
Transition metals and most of their compounds show paramagnetic behaviour.
Give reasons for the following statement:
Zn, Cd, and Hg are soft metals.
The oxidation state of Fe in [Fe(CO)5] is ______.
Account for the following:
Ce4+ is a strong oxidising agent.
Which of the following transition metals shows +1 and +2 oxidation states?
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.
Describe the oxidising action of potassium dichromate and write the ionic equation for its reaction with H2S.
Compare the general characteristics of the first series of the transition metals with those of the second and third series metals in the respective vertical columns. Give special emphasis on the following point:
Ionisation enthalpies
