Chemistry words chapter 6 and 8

  1. Atomic mass unit (amu): a mass unit equal to 1.66 x 10–24 g or 1.661 x 10–27 kg.


  1. Mole: the number 6.02 x 1023; the number of atoms in 12.0000 g of carbon


  1. Standard temperature and pressure: conditions of one atmosphere of pressure and 0 °C.


  1. Empirical formula: the simplest ratio of atoms in a substance.


  1. Atomic mass: the mass of an atom's protons and neutrons expressed in atomic mass units (amu) on the periodic table; on the periodic table, calculated as a weighted average that reflects isotope abundance.


  1. Formula Mass: the sum of the atomic masses of all atoms in a chemical formula expressed in atomic mass units (amu); also known as molecular mass for covalent substances.


  1.  Standard molar volume: the amount of space taken up by 1 mole of any gas at standard temperature (0 °C) and pressure (101.325 kPa); equal to 22.4 L.


  1. Molecular formula: the exact number and types of atoms in a molecule.


  1. Molar mass: the mass of one mole of a substance; the term formula mass is used for ionic substances and molecular mass for covalent substances.


  1. Molecular Mass: the formula mass of a covalent compound.


  1. Hydrate: a compound that has water attached to its structure.


  1. Advagrado’s number:the number of atoms contained in one mole, 6.02 x 1023.


  1. Anhydride: A compound that contains no water particles.


  1. Molecular weight: the mass in grams of one mole of an element or compound - identical to formula mass and molecular mass.


  1. Stoichiometry: the study of the amounts of substances involved in a chemical reaction.


  1. Actual yield: the amount obtained in the lab by actual experiment.


  1. Mole ratio: a ratio comparison between substances in a balanced equation, obtained from the coefficients in the balanced equation; the ratio allows for the conversion of one substance to another substance by using molar equivalent amounts.

  2.  Percent yield: the ratio of the amount of product actually obtained by experiment (actual yield) as compared to the amount of product calculated theoretically (theoretical yield) multiplied by 100.


  1.  Excess reactant: the substance that remains after the reaction is complete.


  1.  theoretical yield: expected amount produced if everything reacts completely.


  1. Limiting reactant: the substance that is used up first during a reaction.