Correct statements from the following are Choose the correct answer from the options given below :
- A, B and C Only
- A, C and D Only
- A and C Only
- B and D Only
Answer
(2) A, C and D Only
Solution
A. Cr2O72- + 14H+ + 6Fe2+ 2Cr3+ + 6Fe3+ + 7H2O, i.e. FeSO4 is oxidised to Fe2(SO4)3 ⇒ correct.
B. Sodium dichromate is hygroscopic and very soluble, so it cannot be weighed accurately; potassium dichromate is the primary standard ⇒ incorrect.
C. 2CrO42- + 2H+ Cr2O72- + H2O; the change depends on pH ⇒ correct.
D. In Cr2O72- two CrO4 tetrahedra share one O atom; the Cr–O–Cr bond angle is 126° ⇒ correct.
∴ A, C and D only
Answer: (2)