Chemistry uses metric units for measurements, according to Chemtutor, LLC. Qualitative analysis expresses the weight of a solid constituent in gram-based units and the volume of a liquid in liter-based units.
According to DataSegment.com, chemical analysis also consists of qualitative analysis, which determines what kind of constituent a compound consists of, rather than how much of something it consists of. The importance in differentiating the two types of analyses lies in the fact that different tests exist for each type.
Weighing a constituent on a scale to determine how much you have represents a quantitative test. Testing a liquid with litmus paper represents a qualitative test because it tells you what you have--an acid, base or neutral substance.