Let's analyze each of the given statements one by one:
Option A: The oxidation number of Cr in
CrO5 is +6 .
To determine the oxidation state of Cr in
CrO5, we need to know the structure of
CrO5. The compound
CrO5 has a peroxide linkage.
Let's calculate the oxidation state:
The oxidation state of O in peroxides
(O22−) is - 1 .
For the other two oxygens (not in peroxides), the oxidation state is -2 each.
Let the oxidation state of Cr in
CrO5 be
x :
x+2(−1)+2(−2)=0 Solving for
x :
‌x−2−4=0‌x=6Thus, the oxidation state of Cr is indeed +6 . Option A is correct.
Option B:
∆H>∆U for the reaction
N2O4(g)⟶2NO2(g), provided both gases behave ideally.
We use the relation:
∆H=∆U+∆n‌RTHere,
∆n is the change in the number of moles of gases. For the reaction:
N2O4(g)⟶2NO2(g)∆n=2−1=1. Since
∆n is positive, we have:
∆H=∆U+∆n‌RTThis implies:
square∆H>∆UHence, Option B is correct.
Option C: pH of
0.1(N)H2SO4 is less than that of
0.1(N)‌HCl at
25∘C.
Option (C) is incorrect because
0.1(N)H2SO4 furnishes less
H+ion than
0.1(N)‌HCl,So,pH of the former solution will be more than the later.
Option D:
(‌)=0.0591 volt at
25∘C.
Let's calculate
(‌) at
25∘C :
‌R=8.314J∕mol⋅K‌T=298K(25∘C)‌F=96485C∕mol So:
(‌)=‌On calculation:
(‌)≈0.0257VThis value is not 0.0591 V . Thus, Option D is incorrect.
Summarizing, the correct statements are Option A and Option B.