Iron is rendered passive by treatment with

Which of the following statements is $NOT$ consistent for transition elements?

Four successive members of the first row transition elements are listed below with their atomic numbers. Which of these elements has the maximum $E^o_{M^{3+}/M^{2+}}$ value?

Iodine is formed when $KI$ reacts with a solution of

When an excess of $KI$ is added to a $CuSO_4$ solution and then $Na_2S_2O_3$ is added to the mixture,which of the following statements is incorrect?

Which of the following ions can reduce dilute acid to give hydrogen gas?