Measuring instantaneous rates is the most direct way of determining the rate law of a reaction, but it is not always convenient, and it may not be possible to do so with precision.
piece (pÄs) n. 1. A thing considered as a unit or an element of a larger thing, quantity, or class; a portion: a piece of string. 2. A portion or part that has been separated from a whole: a piece of pie. 3. An object that is one member of a group or class: a piece of furniture.
1. (Art Terms) the principal or most outstanding item in a series or creative artist's work. 2. (Cookery) the main dish of a meal. [lit: piece of resistance] piece de resistance - The original context for piece de resistance is what one is able to resist by eating the big dishâpangs of hunger. See also related terms for hunger.