i-Butane.

Isobutane (i-butane), mā ē-sái piáu-sī sêng methylpropane, sī hoà-ha̍k-sek siá-chòe C4H10 ê chi̍t-ê alkane hoà-ha̍p-bu̍t; i mā tông-sî sī n-butane ê ī-sèng-thé.