Term
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Definition
6.022 x 10^23
1 mole= 6.022 x 10^23 units |
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Term
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Definition
| A chemical formula shows the ratio by atoms and by moles of elements in the formula |
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Term
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Definition
| atomic mass in grams of 1 mole or 6.022 x 10^23 atoms of an element |
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Term
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Definition
sum of all atomic masses of elements in a formula
"formula weight" and "molecular weight" are often used instead |
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Term
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Definition
| an instrumental technique used to determine atomic mass or molecular mass |
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Term
| 3 types of chemical formulas |
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Definition
1. empirical formula: shows the simplest ratio of the elements present
2. molecular formula: shows the actual number of atoms in one molecule
3. structural formula: shows how the atoms are connected |
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Term
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Definition
mass % of elements in a compound
theoretical % composition--from given formula
%= (n x molar mass of element)/molar mass of compound x 100%
-where n= number of moles of element (from formula) |
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Term
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Definition
| a process in which a substance (or substances) is changed into one or more new substances |
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Term
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Definition
| uses chemical symbols to show what happens during a chemical reaction |
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Term
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Definition
quantitative study of reactants and products
ALWAYS WORK IN MOLES!!! |
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Term
| Limiting Reactant Calculations |
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Definition
-one reagent is excess and some is left over
- other quantity "limits" how much product can be made
-analogous to baking brownies when the mix calls for two eggs and you only have one. Thus you use only half the bag of mix
- the limiting reactant is the one that is completely consumed. It determines the maximum amount (yield) of the products
-whenever quantities of both reactants are given, the limiting reactant must be determined! |
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Term
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Definition
| amount of product actually obtained experimentally |
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Term
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Definition
| amount of product predicted by balanced equation and limiting reagent |
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Term
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Definition
percentage yield = (actual yield/theoretical yield) x 100%
NOTE: the % yield can never be more than 100% |
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