When a $1^o$ alkyl halide reacts with an alkoxide,what is the product obtained?

Explain the preparation of ethers by dehydration of alcohols and its mechanism with a suitable example.

Which among the following is the method for the preparation of ethers?

Preparation of ethers by acid dehydration of secondary or tertiary alcohols is not a suitable method. Give reason.

From Williamson's synthesis,the preparation of which of the following is possible?

Ethers can be prepared by Williamson synthesis in which an alkyl halide is reacted with sodium alkoxide. Di-tertiary ether cannot be prepared by this method. Explain.