An organic compound with the molecular formula $\text{C}_6\text{H}_6\text{O}$ dissolves in NaOH, gives a characteristic colour with neutral $\text{FeCl}_3$ and on treatment with bromine water gives a tri bromo derivative. Which is that compound among the following?

What type of mechanism is followed by dehydration of alcohol to form ether?

The number of primary isomeric alcohols of the molecular formula $\text{C}_4\text{H}_{10}\text{O}$ is

In Gatterman reaction, which of the following catalyst is used?