The freezing point depression of a 0.1 m aqueous solution of a monobasic weak acid HA is 0.20 °C. The dissociation constant for the acid is

Given: $K_f$(H₂O) = 1.8 K kg mol⁻¹, molality ≡ molarity

What is the correct IUPAC name of the compound?

'P' is

On combustion 0.210 g of an organic compound containing C, H and O gave 0.127 g H₂O and 0.307 g CO₂. The percentages of hydrogen and oxygen in the given organic compound respectively are: