Week 4-1 Chemistry Vocabulary
Week 4-2 Vocab
- Chemical equation - A representation of a chemical reaction using symbols of the elements to indicate the amount of substance, usually in moles, of each reactant and product
- Chemical reaction - A process in which atoms of the same or different elements rearrange themselves to form a new substance
- Coefficient – The number placed in front of an element or compound indicating how many of that element or compound are present in the equation
- Subscript – The number placed behind and below an element or compound indicating how many of that element or compound are present in the equation
- Product – The substance or substances that are the result of a chemical reaction
- Reactant – The substance or substances that are present before the chemical reaction
- Decomposition – A type of reaction where a single reactant produces multiple products
- Single replacement – A type of reaction where one element is replaced by another in a compound
- Double replacement – A type of reaction between two compounds where the positive ion of one compound is exchanged with the positive ion of another compound
- Synthesis – A type of reaction where multiple reactants produce a single product
- actual yield: When you do a chemical reaction, this is the amount of chemical that you actually make
- aqueous: dissolved in water
- catalyst: A substance that speeds up a chemical reaction without being used up by the reaction.
- combustion: When a compound combines with oxygen gas to form water,heat, and carbon dioxide
- denature: When the 3-D structure of a protein breaks down due to heat (or pH, etc), it's said to be denatured
- empirical formula: A reduced molecular formula. If you have a molecular formula and you can reduce all of the subscripts by some constant number, the result is the empirical formula.
- emulsion: When very small drops of a liquid are suspended in another. An example of an emulsion is salad dressing after you've shaken it up.
- entropy: A measurement of the randomness in a system.
- enzyme: A biological molecule that catalyzes reactions in living creatures.
- first law of thermodynamics: The energy of the universe is constant. It's the same thing as the Law of conservation of energy.
Stoichiometry- The art of figuring how much stuff you'll make in a chemical reaction from the amount of each reactant you start with.
Mole - 6.02 x 1023 things.
Conservation of mass – mass of reactants = mass of products
Molar mass- The mass of one mole of particles.
Mole ratio - The ratio of moles of what you've been given in a reaction to what you want to find. Handy in stoichiometry
Product- The thing you make in a chemical reaction.
Reactant- The stuff you have before a reaction takes place.
Excess - Having more than what you need.
Unknown quantity– An amount that you do not knowKnown quantity– An amount that you do knowVocab 4-5
accuracy: When you measure something, the accuracy is how close your measured value is to the real value.
precision: A measurement of how repeatable a measurement is.
theoretical yield: The amount of product which should be made in a chemical reaction if everything goes perfectly.
actual yield: When you do a chemical reaction, this is the amount of chemical that you actually make.
percent yield: The actual yield divided by the theoretical yield, times 100.
limiting reactant: If you do a chemical reaction and one of the chemicals gets used up before the other one.
ideal reaction: a reaction in which all of the reactants are converted into products.
inhibitor: A substance that slows down a chemical reaction.
hydroxide ion: The OH- ion, made famous by bases.
aqueous: dissolved in water.vocab 4-6
Barometer - a device for measuring atmospheric pressure
Diffusion - spontaneous mixing of the particles of two substances caused by their random motion
Effusion - diffusion through a pore or hole
Ideal gas - a hypothetical gas that exactly obeys the ideal gas law. A real gas approaches ideal behavior at high temperature and/or low pressure
Kinetic molecular theory - a model that assumes that an ideal gas is composed of tiny particles (molecules) in constant motion
Partial pressure - the independent pressures exerted by different gases in a mixture
Pressure - the force per unit area on a surface
Standard temperature and pressure (STP) - the condition 0oC and 1 atmosphere of pressure
Volatile - is easily evaporated
Kelvin - A unit used to measure temperature. One Kelvin is equal in size to one degree Celsius. To convert between degrees Celsius and Kelvins, simply add 273 to the temperature in degrees Celsius to get Kelvin.