How do primary, secondary and tertiary alcohols differ in terms of their oxidation ?

Explanation

Oxidation of alcohols with acidified `K_(2)Cr_(2)O_()` gives different oxidation products
(i) `underset("Ethanol")(CH_(3)-CH_(2)OH overset((O))underset(-H_(2)O) to underset("Acetaldehyde")(CH_(3)-CHO overset((O)) to underset("Acetiec acid")(CH_(3)COOH)`
(ii) `CH_(3)-underset(OH)underset(|)CH-CH_(3) overset((O))underset(-H_(2)O) to CH_(3)-CH_(3)COOH`
(iii) `CH_(3)-underset(CH_(3))underset(|)overset(CH_(3))overset(|)C-OH overset((O))underset(-H_(2)) to CH_(3)-underset("2-methyl propane")underset(|)C=CH_(2) overset(O) to CH_(3)- underset("Acetic acid") underset(CH_(3)COOH) underset(darr)(CO)-CH_(3) + underset("Formic acid")+HCOOH`