Homogeneous mixturesHeterogeneous mixturesThe substances are completely mixed together in these mixturesThe substances remain separate in these mixturesThey have uniform compositions throughout their massThey have non−uniform compositions throughout their massThey have no visible boundaries of separation between the constituentsThey have visible boundaries of separation between the constituentsSalt in water, sugar in water are examples of homogeneous mixturesMixtures of sodium chloride and iron filings, oil and water are examples of heterogeneous mixtures