Important Vocabulary
Limiting and Excess Reagent
Molar Relationships
Theoretical and Percent Yield
Percent Composition
100
What is a mole?
An unit of measurement that represents 6.02 x 10^23.
100
What is the limiting reagent?
The substance that prevents the chemical reaction from producing more, it is all used up before the other reagents.
100
What are the three main unit of measurements that moles are converted to?
Particles (atoms), grams, and gas volume
100
What is theoretical yield?
The amount predicted by a stoichiometric calculation based off the amount of moles that go in the reaction, this is the maximum amount of products. This represents the ideal reaction, with no occurs or unexpected losses.
100
What is percent composition?
The percentage of each element in a compound.
200
What is Stoichiometry?
The relationship between amounts of substances that go into a reaction.
200
What is the excess reagent?
The substance that is left over when the reaction is over, it is the one with more than the other (limiting) reagent.
200
How do you convert moles to particles (atoms)?
Multiply the moles by (6.02 x 10^23/1mol) and fix the scientific notation if needed.
200
What is actual yield?
The amount of product that is truly made in a chemical reaction, it is measured.
200
What is the percent composition of C2H5OH?
52% C 13% H 35% O
300
What is empirical formula?
A formula that gives the amounts of an element that is present in a compound, it does not tell you the number of atoms.
300
What is the limiting reagent in the following reaction? A 50.6 g sample of Mg(OH)2 is reacted with 45.0 g of HCl according to the reaction: Mg(OH)2 + 2 HCl --> MgCl2 + 2 H2O
HCl
300
How do you convert moles to grams?
Multiply the moles by (molar mass of the substance/1mol)
300
What is percent yield?
The ratio of the actual yield of a product in a chemical reaction to the theoretical yield as a percent.
300
What is the percent composition of glucose, C6H12O6?
40% C 6.71% H 53.29% O
400
What is Avogadro's Number?
The number a mole represents (6.02 x 1023), it is the number of basic particles.
400
For the combustion of sucrose: C12H22O11 + 12O2 ---> 12CO2 + 11H2O there are 10.0 g of sucrose and 10.0 g of oxygen reacting. Which is the excess reagent?
Sucrose
400
How do you covert moles to gas volume?
Multiply the moles by (24.4L/1mol)
400
How do you calculate percent yield?
Place the actual yield over the theoretical yield and multiply by 100 to get a percent.
400
What is the percent composition of KNO3?
38.67% K 13.86% N 47.48% O
500
What are spectator ions?
Ions that do not change in a chemical reaction, they are the same on the reactants side as they are the products.
500
How much of the excess reagent will be left from the reaction of 28.2 g of N2 and 15.8 g ofH2? N2 + 3H2 → 2NH3
9.71 g H2
500
How many grams are in 2.4 moles of sulfur?
77 grams
500
If I start with 5 grams of C3H8, what is my theoretical yield for water? C3H8 + 5O2 --> 3CO2 + 4H2O
8.2 grams
500
What is the percent composition of H2SO4?
2.06% H 32.29%S 65.26% O
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