A negatively charged particle
An extremely small electrically-neutral particle
The sum of the total number of protons, Z, and the total number of neutrons, N. The symbol is A.
Atomic mass number
Number of protons in the nucleus.
The weighted average of the masses of all of its natural occurring isotopes
Atomic weight of an element
A positively charged particle
The electrochemical joining of atoms through this interaction of their electrons.
A representation of a chemical compound
A bond in which one or more electrons from an atom pair off with one or more electrons from another atom and form overlapping electron shells in which both atoms share the paired electrons
Tendency for an atom to attract electrons. The atoms of different elements have different affinities for electrons or
A chemical formulas containing the ratios of atoms present in a compound but do not provide information about molecular composition
The point at which the rates of the forward reaction and reverse reaction are exactly equal for a chemical reaction if the conditions of reaction are constant
The mass, in grams, of a mole of atoms
Gram atomic weight (GAW)
The mass, in grams, of a mole of molecules
Gram molecular weight (GMW)
Explain Isotopes, Isotones, Isobars, Dipoles, Cations, Anions
- Isotopes are atoms of the same element(number of protons) but have different number of neutrons, i.e. H1, H2
- Isotones have the same neutron number N, but different proton number
- Isobar have the same mass number (A)
- Dipoles are molecules that have a polar covalent bond. i.e. Water H2O
- Cations are positive charge particles resulting from an ionic bond
- Anions are negative charge particles resulting from an ionic bond
A sample contains 700ml of a 0.25 molar solution of HCl and water (H2O) How many moles of HCl are there?
- 0.25(M) = Moles of solute / 0.7 liters
- Moles of solute = 0.25(M) x 0.7liters
- Moles of solute = 0.175 moles of HCl
3 ounces of NaCl gets into a 15,000 gallon system. How many ppm of chloride is in the system
- 3 ounces = 85,049 milligrams
- 15,000 gallons = 56,781 liters
- ppm = 85,049 mg/56,781 l
- ppm = 1.497 mg/l of NaCl
- Cl = 35 AMU
- NaCl = 58 AMU
- 35 AMU / 58 AMU is the ratio of Cl in NaCl
- 0.603 ratio of Cl in NaCl
- 1.497 mg/l NaCl x 0.603 = 0.903 mg/l Cl
A homogeneous mixture of solute and solvent
Formed when one or more electrons are wholly transferred from one element to another, and the force of attraction due to the opposing charges holds the elements together
In a chemical reaction the total mass of the products equal the total mass of the reactants
Law of Conservation of Mass
No matter how a given chemical compound is prepared, it always contains the same elements in the same proportions by mass
Law of Definite Proportions
If two elements combine together to form more than one compound, then the masses of one of these elements combining with a fixed mass of the other are in a simple ratio to one another
Law of Multiple Proportions
Bonds where the atoms achieve a more stable configuration by sharing the electrons in their outer shell with many other atoms
Two substances placed together in a container, in any ratio and the composition is not of fixed proportion
A concentration of a solution, equal to the ratio of moles of solute per liter of solution. A one molar solution contains one mole of solute in one liter of solution
The quantity of a pure substance that contains 6.022 × 1023 units (atoms, ions, molecules, or elephants) of that substance. In other words, a mole is Avogadro's number of anything
Chemical formula that indicates the exact numbers of each atom that combine to form a molecule.
The total weight of the individual atoms of a molecule (maybe grams or AMUs).
Groups or clusters of atoms held together by means of chemical bonding
The number of equivalents of solute dissolved in one liter of solution
A measure of the electric charge that an atom or group possesses. The charge is based on the number of electrons in the outer valence shell and the number of electrons required to complete the electron shell.
A concentration of a solution in units of one part of solute to one billion parts solvent
A concentration of a solution in units of one part of solute to one million parts solvent
Groups of atoms that remain together in many chemical reactions and act like single atoms or ions
A compound composed of positive and negative ions held together with an ionic bond.
When a solute is added to a solvent, there is a limit to the amount that will dissolve under a particular set of temperature and pressure conditions. When this limit is reached, the concentration of the solution reaches a maximum value under the existing conditions and the solution is said to be saturated. A saturated solution is one in which the dissolved and undissolved solutes are in equilibrium at a given temperature
The maximum amount of a substance which will dissolve in a given amount of solvent at a specific temperature
The substance that dissolves in a solution
The material that dissolves the other substance(s) in a solution. It is the dissolving medium
Under certain conditions, it is possible for a solvent to contain more dissolved solute than the saturation concentration. Such a solution is said to be supersaturated. This can occur if the environmental conditions change for a solution that is saturated. If a solution exists for a saturated condition and the temperature and pressure conditions are changed, more solute may remain in solution than expected for those conditions.
When a solute is added to a solvent, there is a limit to the amount that will dissolve under a particular set of temperature and pressure conditions. If this limit is not reached, the solution is said to be unsaturated
The outermost shell of an atom is the ______ shell
Attractions between the molecules of nonpolar covalent substances. These forces are generally believed to be
caused by a temporary dipole, or unequal charge distribution, as electrons constantly move about in an atom, ion, or molecule.
Van der Waals forces
Explain the different types of bonds
- Ionic bonds: Formed when one or more electrons are wholly transferred from one element to another and the force of attraction due to opposing charges holds the elements together.
- Covalent bonds: Formed when one or more electrons from an atom pair off with one or more electrons from another atom and form overlapping electron shells in which both atoms share the paired electron
- Metallic bonds: Bonds where the atoms achieve a more stable configuration by sharing the electrons in their outer shell with many other atoms
- Van der Waals forces: Attractions between the molecules of non polar covalent substances. These forces are generally believed to be caused by a temporary dipole or unequal charge distribution as electrons constantly move about in an atom, ion, or molecule.
Define Oxidation number, chemical formula, and radical
- Oxidation number: A measure of the electric charge an atom or group possesses. The charge is based on the number of electrons in the outer valence shell and the number of electrons required to complete the shell
- Chemical formula: A representation of a chemical compound. It is made up of one or more chemical symbols together with subscript numbers to indicate the quantity of each atom present
- Radical: Groups of atoms that remain together in many chemical reactions and act like single atoms or ions
Determine the oxidation numbers of Na, Ca, Fe, Cu, O, and Br
- Found under the name of the element on the periodic table
- Na +1, Ca +2, Fe +2/+3, Cu +1/+2, O -2, Br +-1,5
Write the formula for
Write the formula for
Balance the reaction H2O + Li2O2 > LiOH + O2
2H2O + 2Li2O2 > 4LiOH + O2
What are the catalysts? Describe in terms of activation energy.
A catalyst is a chemical substance that increases the rate of a chemical reaction by reducing the activation energy, but which is left unchanged by the reaction. A catalyst accelerates the chemical reaction.
An ounce of Li2SO4 is added to a 5,000 gallon tank. How many ppm of Li2SO4 are present?
- ppm = mg solute / liters of solution
- 1 ounce = 28,349 mg
- 5,000 gallons = 18,927 liters
An ounce of NaCl is allowed into 1,000 gallons of H2O. How many ppb are present?
- ppb = micrograms (ug) of solute / liters of solution
- 1 ounce = 28,349,523 micrograms
- 10,000 gallons = 3,785 liters
An ounce of HF is added to a 20,000 gallon system. How many ppb of F- is in the system
- The ratio of F- to HF is 0.949. Divide the Atomic weight of F- by the total weight of HF.
- .949 (28,349,523 (1oz to ug) = 26,921,245
- 20,000 gallons = 75,708
What is the Molarity & Normality of 1 mol of H2SO4 in 1L of H2O
- M = moles solute / liter solution = 1 mol / 1 L = 1 molar
- N = equivalents solute / liter solution = 2 eq / 1 L = 2 N