Step 1: Write the molecular formula.
Hypochlorous acid has the formula \(\mathrm{HOCl}\). Step 2: Assign known oxidation states.
Hydrogen generally has an oxidation state of \(+1\) and oxygen has an oxidation state of \(-2\). Step 3: Calculate oxidation state of chlorine.
Let the oxidation state of chlorine be \(x\). Then:
\[
(+1) + x + (-2) = 0
\]
\[
x = +1
\] Step 4: Conclusion.
Thus, the oxidation state of chlorine in hypochlorous acid is \(+1\).