1–Butyne on reaction with hot alkaline $KMn{O}_4$ followed by acidification gives?

1–Butyne on reaction with cold alkaline $KMn{O}_4$ will produce propanoic acid and carbon dioxide

 ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}\text{C}\equiv \text{CH }\stackrel{{\text{hot alkaline KMnO}}_{\text{4}}}{\to }{\text{ CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{COOH + CO}}_{\text{2}}$