MCQ
Oxidation state of $Fe$ in $F{e_3}{O_4}$ is
  • A
    $\frac{3}{2}$
  • B
    $\frac{4}{5}$
  • C
    $\frac{5}{4}$
  • $\frac{8}{3}$

Answer

Correct option: D.
$\frac{8}{3}$
(d) $\mathop F\limits^ * {e_3}{O_4}$

$3x + ( - 8) = 0$; $3x - 8 = 0$

$3x = 8$; $x = \frac{8}{3}$.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Assign true $(T)$ and false $(F)$ for following statements and select correct option for your answer

$(a)\, IP$ of $O_{(g)}$ is less than $IP$ of $O_{(g)}^ - $
$(b)\, IP$ of $Ne_{(g)}$ is greater than $IP$ of $Ne_{(g)}^ + $
$(c)\, EA$ of $O_{(g)}^ + $ is greater than $EA$ of $O_{(g)}$
$(d)\, IP$ of $N_{(g)}$ is greater than $IP$ of $N_{(g)}^ + $

Uracil is base present in $RNA$ with the following structure. $\%$ of $N$ in uracil is $............$.

Given :

Molar mass $N =14\,g\,mol ^{-1} ; O =16\,g\,mol ^{-1} ; C =12\,g\,mol ^{-1} ; H =1\,g\,mol ^{-1}$;

Give the symbol of the elements of lowest atomic number that has three $2p$ electrons
Which statement is not correct for nitrogen
Incorrect statement for the use of indicators in acid-base titration is :
At $300\, K$ and $1$ atmospheric pressure, $10\, mL$ of a hydrocarbon required $55\, mL$ of $O_2$ for complete combustion, and $40\, mL$ of $CO_2$ is formed. The formula of the hydrocarbon is
$2 \mathrm{SO}_{2}(\mathrm{~g})+\mathrm{O}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{SO}_{3}(\mathrm{~g})$

In an equilibrium mixture, the partial pressures are

$P_{S O_{3}}=43\,\mathrm{kPa} ; \quad P_{O_{2}}=530 \,\mathrm{~Pa}$ and

$\mathrm{P}_{\mathrm{SO}_{2}}=45\, \mathrm{kPa}$ The equilibrium constant $\mathrm{K}_{\mathrm{p}}=......\times 10^{-2} .$ (Nearest integer)

Which of the following compounds will behave as a reducing sugar in an aqueous $KOH$ solution ?
The decomposition of formic acid on gold surface follows first order kinetics. If the rate constant at $300\, K$ is $1.0 \times 10^{-3} s ^{-1}$ and the activation energy $E _{ a }=11.488\, kJ\, mol ^{-1},$ the rate constant at $200\, K$ is ............  $\quad \times 10^{-5} s ^{-1} .$

(Round of to the Nearest Integer).

(Given : $\left. R =8.314\, J\, mol ^{-1} K ^{-1}\right)$

Of the following, which has three electron bond in its structure