Butene-1 may be converted to butane by reaction with

The correct order of increasing basic nature for the bases NH₃, CH₃NH₂ and (CH₃)₂ NH is

In the coordination compound, K₄[Ni(CN)₄], the oxidation state of nickel is :

Bottles containing C₆H₅l and C₆H₅CH₂I lost their original labels. They were labelled A and B for testing A and B were separately taken in test tubes and boiled with NaOH solution. The end solution in each tube was made acidic with dilute HNO₃ and then some AgNO₃ solution was added. Substance B gave a yellow precipitate. Which one of the following statements is true for this experiment?