Unit 3

Question 1

describe combination reaction

Answer 1

-joining of 2+ elements to form a single product

Question 2

describe decomposition reaction

Answer 2

conversion of a single reactant to 2+ products

Question 3

describe replacement reactions

Answer 3

-either double or single
-1 or 2 element replaces another in a compound to form a different compound and element as products
-replacing atoms

Question 4

what does the Law of conservation of mass state?

Answer 4

-atoms cannot be created or destroyed in a chemical reaction
-coefficients are used to balance an equation
-a balanced equation has the same # of atoms of each element on both sides of the equation

Question 5

describe oxidation-reduction reactions

Answer 5

-oxidation = loss of electrons GAIN OF OXYGEN ATOMS / LOSS OF HYDROGEN ATOMS
-reduction - gain of electrons LOSS OF OXYGEN ATOMS / GAIN OF HYDROGEN ATOMS
-*these occur together in a single reaction

Question 6

reduction forms what?

Answer 6

an anion

Question 7

oxidation forms what?

Answer 7

cation

Question 8

what is a redox reaction?

Answer 8

-transfer of electrons from one element to another

Question 9

what is the reducing agent?

Answer 9

-the species that causes another to gain electrons/become reduced
-always the opposite (species that is oxidized = reducing agent)

Question 10

what is the oxidizing agent?

Answer 10

-the species that causes another to lose electrons/become oxidized
-(species that is reduced = oxidizing agent)

Question 11

what are the 4 rules for assigning oxidation states?

Answer 11

-free elements have an oxidation state of 0
-monoatomic ions have an oxidation state equal to their charge
-the sum of oxidation states of all the atoms in a compound = 0
-the sum of oxidation states of all the atoms in a polyatomic ion
= charge of the ion
-group 1 metals have an oxidation state of +1 in all their compounds
- group 2 metals = +2

Question 12

1 mole is equal to how many molecules?

Answer 12

6.022 x 10 ^23

Question 13

what is formula weight?

Answer 13

-sum of the atomic weights of all the atoms in a compound reported in amu

Question 14

what is molar mass?

Answer 14

-mass of 1 mole of any substance reported in g/mol

Question 15

what is a limiting reactant?

Answer 15

-limits the amount of product that can be formed in a reaction
-*the reactant that forms the least amount of product

Question 16

what is theoretical yield?

Answer 16

-the max amount of product that can be obtained in a reaction

Question 17

what is percent yield?

Answer 17

-the amount of product obtained from a reaction
- percent yield = ( actual yield / theoretical yield ) x 100

Question 18

what are the features of gases?

Answer 18

-always miscible (2 diff. gases will mix completely & form a homogeneous mixture)
-compressible
-exert pressure (the force of collisions that takes place between the particles and the object)

Question 19

what is a barometer?

Answer 19

-tool to measure atmospheric pressure (atm)

Question 20

what is pressure (gas)?

Answer 20

-when gas particles collide with the walls of a container, they exert a pressure
-pressure = force / area

Question 21

describe Boyle’s Law

Answer 21

-for a fixed amount of gas at a constant temperature, the pressure and volume of a gas are inversely related (if one quantity increases, the other decreases)
- pressure x volume = constant
- P1V1 = P2V2

Question 22

describe Charle’s Law

Answer 22

-for a fixed amount of gas at a constant pressure, the volume of a gas is proportional to its Kelvin temperature direct relationship (if one quantity increases, so will the other)
- Volume / Temperature = constant
- V1/T1 = V2/T2