An equivalent is the amount of a substance that reacts with an arbitrary amount of another substance in a given chemical reaction. It is an archaic unit of measurement that was used in chemistry and the biological sciences. The mass of an equivalent is called its equivalent weight. In biological systems, reactions often happen on small scales, involving small amounts of substances, so those substances are routinely described in terms of milliequivalents, the prefix milli- denoting a factor of one thousandth (10−3). Very often, the measure is used in terms of milliequivalents of solute per litre of solution. This is especially common for measurement of compounds in biological fluids; for instance, the healthy level of potassium in the blood of a human is defined between 3.5 and 5.0 mEq/L. Website: https://zealacademy.info/ Facebook: / kapsaustralia Instagram: / academy.zeal Linked In: / phar. . Whatsapp: https://wa.me/919544500704