Make up the reaction equations of a) propyl-butyl ether b) acetic-hexyl ether c) octane-butyl ether

An ester is a product of the interaction of an acid and alcohol at the site of their functional groups:
a) propyl – butyl ether – propanoic acid and butyl alcohol:
CH3 – CH2 – COOH + C4H9 – OH = CH3 – CH2 – CO – C4H9 + H2O
b) acetic-hexyl ether – acetic acid and hexyl alcohol –
CH3 – COOH + C6H13 – OH = CH3 – CO – C6H13 + H2O
c) octane – butyl ether – octanoic acid and butyl alcohol –
CH3-CH2 – CH2 – CH2 – CH2 – CH2 -CH2 – COOH + C4H9 – OH = CH3 – (CH2) 6 – CO – C4H9 + H2O