The main difference between mixtures and compounds is that a mixture may have been mixed without the need to use chemicals. This means that the liquids can be mixed through physical means. A compound would need to use chemicals to ensure that they will mix properly. Another difference between the two is the variable composition.
You can expect that compounds will not have variable compositions while mixtures will always have. Take note that you cannot tell the difference between mixtures and compounds if you would base things solely on the volume of the items that are being measured or used. Mixtures and compounds are normally used in varying ways.