Question

molar mass of acetic acid in aqueous solution as determined by the use of colligative properties is approximately double of the expected value why?​

Answer 1

ANSWER

Determination of the molar mass of acetic acid in benzene using freezing point depression is affected by association.

In benzene solution, two molecules of acetic acid associate to form one molecule.

Hence, the observed molar mass will be twice the actual molar mass.

Answer 2

「ᴛʜᴇ ᴍᴏʟᴀʀ ᴍᴀss ᴏғ ᴀᴄᴇᴛɪᴄ ᴀᴄɪᴅ ɪɴ ᴀ sᴏʟᴜᴛɪᴏɴ ᴏғ ʙᴇɴᴢᴇɴᴇ sᴏʟᴠᴇɴᴛ ɪs ɢʀᴇᴀᴛᴇʀ ᴛʜᴀɴ ɪᴛs ғᴏʀᴍᴜʟᴀ ᴍᴏʟᴀʀ ᴍᴀss ʙᴇᴄᴀᴜsᴇ ᴛᴡᴏ ᴄʜ3ᴄᴏᴏʜ ᴍᴏʟᴇᴄᴜʟᴇs ғᴏʀᴍ ᴀ ᴅɪᴍᴇʀ (ᴄʜ3ᴄᴏᴏʜ)2 ɪɴ sᴏʟᴜᴛɪᴏɴ. ʙᴜᴛ ᴡᴇ ᴋɴᴏᴡ ᴛʜᴀᴛ ᴛʜᴇ ᴍᴏʟᴀʀ ᴍᴀss ɪs ᴅᴇғɪɴᴇᴅ ᴀs ᴛʜᴇ ᴍᴀss ᴏғ 6.023 x 1023 ᴘᴀʀᴛɪᴄʟᴇs ᴏғ ᴛʜᴇ sᴜʙsᴛᴀɴᴄᴇ. ɪɴ ᴄᴀsᴇ ᴏғ ᴀ ɴᴏʀᴍᴀʟ sᴏʟᴜᴛᴇ ʟɪᴋᴇ ᴄʜ3ᴄᴏᴏʜ, ᴛʜᴇ ᴍᴏʟᴀʀ ᴍᴀss ᴏғ ᴀᴄᴇᴛɪᴄ ᴀᴄɪᴅ ɪs ᴇǫᴜᴀʟ ᴛᴏ ᴛʜᴇ ᴍᴀss ᴏғ 6.023 x 1023 ᴍᴏʟᴇᴄᴜʟᴇs ᴏғ ғᴏʀᴍᴜʟᴀ ᴄʜ3ᴄᴏᴏʜ. ᴡʜɪʟᴇ ɪɴ sᴏʟᴜᴛɪᴏɴ ᴛʜᴇ sᴏʟᴜᴛɪᴏɴ ᴅɪᴍᴇʀɪsᴇs ᴀɴᴅ ʙᴇᴄᴏᴍᴇs ᴀ ʙɪɢɢᴇʀ ᴍᴏʟᴇᴄᴜʟᴇ ʟɪᴋᴇ (ᴄʜ3ᴄᴏᴏʜ)2.」♡