CHEMICAL REACTIONS AND STOICHIOMETRY

Question 1

Chemical equation

Answer 1

Symbolic representation of chemical reaction in the form of symbols and formulas

Question 2

Important symbols in chemical equation

Answer 2

(s) = solid, (l) = liquid, (g) = gas, (aq) = aqueous

Question 3

Aqueous

Answer 3

Dissolved in water

Question 4

Law of conservation of mass

Answer 4

Mass is never created or destroyed. Every reactant atom/molecule consumed in reaction must produce products in the ratios given by their coefficients in a balanced equation

Question 5

Stoichiometry

Answer 5

Using relationships between reactants and products in an equation to determine the quantitative data (equation must be balanced before doing this)

Question 6

Conversions

Answer 6

Atoms/molecules –> mol –> g, g –> mol –> atoms/molecules (6.022x10^23)

Question 7

Theoretical yield

Answer 7

Maximum number of product that can be attained from chemical reaction (based on amount or LR)

Question 8

Actual yield

Answer 8

Measured amount of product actually obtained

Question 9

Percent yield

Answer 9

Tells us how well a reaction is working (Actual yield/theoretical yield x 100%)

Question 10

Limiting reagent

Answer 10

Reactant that is fully consumed in a reaction

Question 11

Excess reagent

Answer 11

Reactant that is not fully consumed in reaction

Question 12

Reaction stoichiometry with pure liquids (2)

Answer 12

• Liquids can either be solutions (solutes dissolved in solvent) or pure liquids
• Pure liquids can be measured with either mass or volume. if measured by volume, density must be calculated to find mass before mole conversion

Question 13

Solution

Answer 13

Homogenous mixture of 2 or more substances (usually H2O + salt)

Question 14

Solvent

Answer 14

Substance that dissolves a solute (majority)

Question 15

Solute

Answer 15

Substance that gets dissolved (minority)

Question 16

Concentration

Answer 16

How much solute dissolved in the solvent

Question 17

Unit of concentration

Answer 17

M (molarity) or mol/L. M = mol/L

Question 18

Dilution

Answer 18

Common lab technique to make solution less concentrated. Total moles of solute present should be the same before and after dilution (mol 1 = mol 2, mol = M x V, M1V1 = V1V2

Question 19

Titration

Answer 19

Used to determine concentration of specific solute in a solution by reacting it with another reagent whose concentration we know

Question 20

Primary standard

Answer 20

Substance that can be weighed accurately and used to make a solution whose concentration we know

Question 21

Secondary standard

Answer 21

Substance whose concentration can be determined by reacting with a primary standard

Question 22

Equivalence point

Answer 22

Occurs when just enough standard has been added to react with all of the analyte (visualized with an indicator)

Question 23

DIATOMIC IONS

Answer 23

• H2
• N2
• F2
• O2
• Cl2
• I2
• Br2
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