Amount of substance in use in chemical engineering in the United States is the pound-mole, having the symbol lb-mol. One pound-mole is . When quoting an amount of substance, it is necessary to specify the entity involved, unless there is no risk of ambiguity. One mole of chlorine could refer either to chlorine atoms, as in 58.44 g of sodium chloride, or to chlorine molecules, as in 22.711 liters of chlorine gas at STP. The simplest way to avoid ambiguity is to replace the term "substance" by the name of the entity or to quote the empirical formula. For example: Amount of substance
Cutting compound eventually strip all the paint from the surface, which both is less appealing and offers less chemical resistance. Waxing to protect the newly exposed surface is an important part of maintenance. Cutting compound Cutting compound consists of an abrasive suspended in a paste. Like most abrasives, it comes in various grit sizes dependent upon how much matter is to be removed. It is used on automotive paintwork to cut through (abrade) oxidised paint or to polish out scratches in the paintwork. The oxidised paint is duller than fresh paint and the cutting compound is used to expose this fresher surface.