MCQ
Colour of $CrO_4^{^{2 - }}(aq.)$ is not changed by
- Adil. $HCl$
- ✓$NH_3$ solution
- C$CH_3COOH$
- D$NO_2$ gas
✓
Answer
Correct option: B.
$NH_3$ solution
b
$\mathop {CrO_4^{2 - }(aq.)}\limits_{(yellow)} \underset{\begin{subarray}{l}
pH > 7 \\
(Basic)
\end{subarray} }{\overset{\begin{subarray}{l}
(Acidic) \\
pH < 7
\end{subarray} }{\longleftrightarrow}}\mathop {C{r_2}O_7^{2 - }(aq.}\limits_{(Orange)} )$
$\mathop {CrO_4^{2 - }(aq.)}\limits_{(yellow)} \underset{\begin{subarray}{l}
pH > 7 \\
(Basic)
\end{subarray} }{\overset{\begin{subarray}{l}
(Acidic) \\
pH < 7
\end{subarray} }{\longleftrightarrow}}\mathop {C{r_2}O_7^{2 - }(aq.}\limits_{(Orange)} )$
$NH_3$ being basic in solution, does not change yellow colour of $CrO_4\,^{2-}(aq.)$ .
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
In the Hoffmann bromamide degradation reaction, the number of moles of $NaOH$ and $Br_2$ used per mole of amine produced are :
→For which of the following reaction, product formation is favoured at low pressure and low temperature ?
A chemical reaction: $A + B \rightarrow AB , \,B$ is acting as limiting reagent then choose the correct option. The limiting reagent is :
→Assertion : Benzene diazonium salt on boiling with water forms phenol.
Reason : $C -N$ bond is polar
→Reason : $C -N$ bond is polar
Each carbon atom in benzene is in the state of hybridization
Arrange the following $(w, x, y, z)$ in decreasing order of their boiling points
→Benzoic acid has higher molecular weight in benzene and less in water because
The bond order and magnetic behaviour of $\mathrm{O}_{2}^{-}$ion are, respectively:
→Which of the following sequence represents atomic number of only representative elements?
The quantitative estimation of $O_3$ is based on
→