Advertisements
Advertisements
प्रश्न
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
उत्तर
`K_2Cr_2O_7 + 2KOH -> 2K_2CrO_4 + H_2O`
`2K_2CrO_4 + 2HCl -> K_2Cr_2O_7 + 2KCl + H_2O`
APPEARS IN
संबंधित प्रश्न
Explain why is Fe3+ more stable than Fe2+?
Account for the following:
Cr2+ is a strong reducing agent.
Account for the following:
Zn is not considered as a transition element.
Out of Mn3+ and Cr3+, which is more paramagnetic and why ?
(Atomic nos. : Mn = 25, Cr = 24)
Which of the 3d series of the transition metals exhibits the largest number of oxidation states and why?
Explain why Cu+ ion is not stable in aqueous solutions?
What may be the stable oxidation state of the transition element with the following d electron configuration in the ground state of its atom?
3d3
What are the characteristics of the transition elements and why are they called transition elements?
Describe the oxidising action of potassium dichromate and write the ionic equation for its reaction with iodide.
Write the formula of an oxo-anion of Chromium (Cr) in which it shows the oxidation state equal to its group number
Generally transition elements form coloured salts due to the presence of unpaired electrons. Which of the following compounds will be coloured in solid-state?
When acidified \[\ce{K2Cr2O7}\] solution is added to \[\ce{Sn^{2+}}\] salts then \[\ce{Sn^{2+}}\] changes to ______.
Why is \[\ce{HCl}\] not used to make the medium acidic in oxidation reactions of \[\ce{KMnO4}\] in acidic medium?
Which of the following ions show higher spin only magnetic moment value?
(i) \[\ce{Ti^3+}\]
(ii) \[\ce{Mn2+}\]
(iii) \[\ce{Fe2+}\]
(iv) \[\ce{Co3+}\]
EΘ of Cu is + 0.34V while that of Zn is – 0.76V. Explain.
Assertion: Separation of \[\ce{Zr}\] and \[\ce{Hf}\] is difficult.
Reason: Because \[\ce{Zr}\] and \[\ce{Hf}\] lie in the same group of the periodic table.
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?
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.
Among the following pairs of ions, the lower oxidation state in aqueous solution is more stable than the other in:-
Agcl is soluble in NH4OH. The solubility is due to the information of:-
On adding NaOH, solution to the aqueous solution of K2CrO7 the colour of the solution changes from
A complex in which dsp2 hybridisation takes place is ______.
Which of the following ions has the maximum magnetic moment?
Consider the following standard electrode potentials (E° in volts) in aqueous solution:
| Element | M3+/M | M+/M |
| Al | - 1.66 | +0.55 |
| Tl | + 1.26 | -0.34 |
Based on these data, which of the following statements is correct?
Assertion (A): Transition metals have high enthalpy of atomisation.
Reason (R): Greater number of unpaired electrons in transition metals results in weak metallic bonding.
Complete the following reaction and justify that it is a disproportionation reaction:
\[\ce{3MnO^{2-}4 + 4H^+ -> \underline{}\underline{}\underline{}\underline{} + \underline{}\underline{}\underline{}\underline{} + 2H2O}\]
Write the number of unpaired electrons in Cr3+.
(Atomic number of Cr = 24)
‘Spin only’ magnetic moment is the same for which of the following ions?
- Ti3+
- Cr2+
- Mn2+
- Fe2+
- Sc3+
Choose the most appropriate answer from the options given below:
