Acetic anhydride reacts with diethyl ether in the presence of anhydrous $AlCl_3$ to form:

In which of the following reactions is the product an ether?

Explain: In alkoxybenzene,the alkoxy group is ortho-para directing,but why does electrophilic substitution occur mainly at the para-position and to a lesser extent at the ortho-position?

Give the common and $\rm {IUPAC}$ names for the following ether compounds:
$(i) \ CH_3OCH_3$
$(ii) \ C_2H_5OC_2H_5$
$(iii) \ C_6H_5OC_6H_5$
$(iv) \ CH_3OCH_2CH_2CH_3$
$(v) \ CH_3OCH(CH_3)_2$
$(vi) \ C_6H_5OCH_3$
$(vii) \ C_6H_5OCH_2CH_3$
$(viii) \ C_6H_5O(CH_2)_6CH_3$
$(ix) \ C_6H_5OCH_2CH_2CH(CH_3)_2$
$(x) \ CH_3OCH_2CH_2OCH_3$
$(xi) \ C_2H_5OCH_2CH_2OC_2H_5$
$(xii) \ CH_3OCH_2CH_2CH_2OCH_3$
$(xiii) \ CH_3OCH_2CH_2OC_2H_5$
$(xiv) \ \text{Cyclohexyl methyl ether}$

The following is not an appropriate reaction for the preparation of $t$-butyl ethyl ether:
$C_2H_5ONa + CH_3-C(CH_3)_2-Cl \to CH_3-C(CH_3)_2-O-C_2H_5$
$(i)$ What would be the major product of this reaction?
$(ii)$ Write a suitable reaction for the preparation of $t$-butyl ethyl ether.

What is $X$ in the following reaction?