The number of structurally isomeric esters with molecular formula `C_(5H_(10)O` are.

Explanation

(i)`H-oversetoverset(O)(||)(C)-O-CH_(2)-CH_(2)-CH_(2)-CH_(3)` , (ii)`H-oversetoverset(O)(||)(C)-O-oversetoverset(CH_(3))(|)(CH)-CH_(2)-CH_(3)` , (iii)`H-oversetoverset(O)(||)(C)-O-CH_(2)-oversetoverset(CH_(3))(|)(CH)-CH_(3)` , (iv)`H-oversetoverset(O)(||)(C)-O-undersetunderset(CH_(3))(|)oversetoverset(CH_(3))(|)(C)-CH_(3)` , (v)`CH_(3)-oversetoverset(O)(||)(C)-O-CH_(2)-CH_(2)-CH_(3)` , (vi)`CH_(3)-oversetoverset(O)(||)C-O-oversetoverset(CH_(3))(|)(CH)-CH_(3)` , (vii)`CH_(3)-CH_(2)-oversetoverset(O)(||)(C)-O-CH_(2)-CH_(3)` , (viii)`CH_(3)-CH_(2)-CH_(2)-oversetoverset(O)(||)(C)-O-CH_(3)` , (ix)`CH_(3)-oversetoverset(CH_(3))(|)(CH)-oversetoverset(CH_(3))(|)(CH)-CH_(3)`