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.
noun. 1  A thin piece split off from a larger piece; a splinter. 2  a. A rigid device used to prevent motion of a joint or of the ends of a fractured bone. 3  A thin, flexible wooden strip, such as one used in the making of baskets or chair bottoms.  A plate or strip of 1  metal. A bony enlargement of the cannon bone or splint bone of a horse.