Oxidation number of oxygen in potassium super oxide (KO₂) is [UPSEAT 1999, 2002]

(1) – 2

(2) – 1

(3) – 1/2

(4) – 1/4

The compound ${\mathrm{YBa}}_2{\mathrm{Cu}}_3{\mathrm{O}}_7$ which shows superconductivity has copper in oxidation state ........ Assume that the rare earth element Yttrium is in its usual +3 oxidation state [IIT 1994]

(1) 3/7

(2) 7/3

(3) 3

(4) 7

In a balanced equation $H_{2}S{O}_4+xHI\to H_{2}S+y{I}_2+z{H}_{2}O$, the values of x, y, z are

(1) x = 3, y = 5, z = 2

(2) x = 4, y = 8, z = 5

(3) x = 8, y = 4, z = 4

(4) x = 5, y = 3, z = 4

Which of the following pair is having different oxidation number of central atom?

(1) $K_{2}Cr{O}_4$ ,$K_{2}C{r}_2{O}_7$

(2) $H_{2}S{O}_4, H_{2}S{O}_5$

(3) $N{H}_3, N_{3}H$

(4) All of these

Which of the following is not a disproportionation reaction?

(1) $H_2{S}_2{O}_8\to H_{2}S{O}_4+O_2$

(2) $P_4\stackrel{H_{2}O}{\to }P{H}_3+H_{3}P{O}_4$

(3) $H_{2}S{O}_5\to H_{2}S{O}_4+\frac{1}{2}{O}_2$

(4) $S_8+H_{2}O\to H_{2}S+\frac{1}{2}{O}_2$

Oxidation state of 'P' in $Ba\left(HP{O}_3\right)$ is

(1) +1

(2) +2

(3) +3

(4) +4

 $In a KMn{O}_4+bFeS{O}_4+c{H}_{2}S{O}_4$
$\to dF{e}_2{\left(S{O}_4\right)}_3+e{K}_{2}S{O}_4+fMnS{O}_4+g{H}_{2}O,$
$Correct relation is$

(1) (a+e+f) = d

(2) c = g = d + e + f

(3) b = a + d + e + f

(4) All of these 

Oxidation states of C in Toluene is/are

(1) -3

(2) -1

(3) 0

(4) All of these

Highest oxidation number of nitrogen is in

(1) Nitrobenzene

(2) Nitric acid

(3) $N{O}_2$

(4) Both (2) & (3) 

Oxidation state of titanium in pervoskite is

(1) +2

(2) +3

(3) +4

(4) +5