gchem 1

Question 1

What does Z mean?

Answer 1

atomic number

Question 2

What does A mean?

Answer 2

mass number

Question 3

Why are anions larger than cations?

Answer 3

anions are bigger because they have gained electrons which repel each other and take up more space

Question 4

metals are __ atoms with __ held electrons

Answer 4

larger, loosely

Question 5

non-metals are __ atoms with __ held electrons

Answer 5

smaller, tightly

Question 6

Why are larger atoms better at stabilizing charges?

Answer 6

form weaker pi binds because of decrease in overlapping p orbitals

Question 7

What is the difference between electron affinity and electronegativity?

Answer 7

electronegativity - propensity of atom attracting an electron
electron affinity - amount of energy liberated when a molecule or neutral atom acquires an electron from outside

Question 8

What is the first quantum number?

Answer 8

n - shell

Question 9

what is the second quantum number?

Answer 9

l - subshell or orbital

Question 10

What is the 3rd quantum number?

Answer 10

ml - orbital orientation , value from -L to L

Question 11

What is the 4th quantum number?

Answer 11

Ms- spin (+ or -)

Question 12

How many electrons in the s, p, d, f orbital?

Answer 12

2, 6, 10, 14

Question 13

What are the Heisenberg Uncertainty and Pauli Exclusion principles?

Answer 13

Pauli Exclusion principle - no two electrons can all 4 quantum numbers the same

Heisenberg Uncertainty principle- more known ab electron position, the less we know about its momentum

Question 14

What is the formula for the energy of a photon?

Answer 14

E = hf

h- planks constant
f- frequency

Question 15

What is the formula for the energy of a photon?

Answer 15

E= hc/lambda

Question 16

what is radioactive decay?

Answer 16

process by which unstable atoms change their chemical composition over time.

Question 17

What is alpha decay?

Answer 17

loss of one He nucleus, which has a mass of 4 and atomic number of 2

Question 18

What is beta decay?

Answer 18

neutron is changed into a proton - ejection of an electron

Question 19

What is electron capture ?

Answer 19

proton is changed into neutron - via capture of electron

Question 20

What is positron emission?

Answer 20

proton is changed into a neutron- expulsion of positron

Question 21

What is gamma emission?

Answer 21

gamma rays are usually emitted as a byproduct of the types of decay outlined

Question 22

What is half-life?

Answer 22

the amount of time required for exactly one-half of the mass of that substance to disappear due to radioactive decay

Question 23

___ bonding orbitals are higher in energy than __ orbitals

Answer 23

anti, bonding

Question 24

What’s the difference between covalent and ionic bonds?

Answer 24

covalent - 2 nonmetals are bonded (sharing of electrons)

ionic - metal and nonmetal (electrostatic attraction)

Question 25

What makes a good electrolyte?

Answer 25

when compounds dissociate completely in water (ionic compounds are always good electrolytes)

Question 26

Which two elements in the periodic table, if bonded, would create a bond with the maximum possible ionic character?

Answer 26

Francium fluoride

Question 27

What is condosity?

Answer 27

molar concentration of a sodium chloride solution that has the same specific electrical conductance as the solution under test

Question 28

What is bond length?

Answer 28

distance between nuclei of the atoms forming the bond

Question 29

What is bond energy?

Answer 29

energy required to break a bond

Question 30

Energy is ___ to break a bond, energy is __ when a bond is formed

Answer 30

required, released

Question 31

What is the heat of combustion?

Answer 31

the amount of energy released when a molecule is combusted with oxygen

Question 32

The higher the energy of a molecule (less stable), the __ the heat of combustion

Answer 32

higher

Question 33

Why do bonds form?

Answer 33

form bonds when the resulting bond is a lower energy state

Question 34

What is the difference between empirical and molecular formulas?

Answer 34

empirical - lowest possible number of moles that keep the original ratio in a chemical formula CH2O molecular- the actual moles of each element C6H12O6

Question 35

How do you calculate percent mass?

Answer 35

percent mass= mass of one element of the compound/total mass of compound x 100

Question 36

how do you derive a chemical formula from percent mass?

Answer 36

1. change percent mass of each element to grams 2. convert the grams into moles by dividing by molar mass 3. look at the element with lowest number of moles, divide into other molar amounts for each element to find ratio

Question 37

What is the chemical formula for chlorate?

Answer 37

ClO3-

Question 38

What is the chemical formula for nitrite and nitrate?

Answer 38

nitrite - NO2- | nitrate - NO3-

Question 39

What is the chemical formula for chlorate and perchlorate?

Answer 39

chlorate - ClO3- | perchlorate - ClO4-

Question 40

What is the chemical formula for hypochlorite?

Answer 40

ClO-

Question 41

What is the chemical formula for carbonate and bicarbonate?

Answer 41

carbonate - CO3 2- | bicarbonate - HCO3-

Question 42

What is the chemical formula for sulfate?

Answer 42

SO4 2-

Question 43

What is the chemical formula for manganate?

Answer 43

MnO4 2-

Question 44

What is the chemical formula for permanganate?

Answer 44

MnO4-

Question 45

How do you name acids, where the ion ends in "ate"

Answer 45

"ic" nitrate turns into nitric acid

Question 46

If an ion ends in "ite" the acid ends with __

Answer 46

"ous" nitrite -> nitrous acid

Question 47

If there is a single ion, the acid is named with __ as the prefix and __ as the suffix

Answer 47

hydro, ic | iodide -> hydroiodic acid

Question 48

What is the difference between atomic weight and molecular weight?

Answer 48

atomic - mass of one mole of any atom | molecular - sum of the masses of each element

Question 49

How do you calculate the limiting reagent?

Answer 49

1. have a balanced eq. | 2. convert to moles to see which reactant is less

Question 50

What is theoretical yield, actual yield and percent yield?

Answer 50

theoretical - amount of product in grams that would be produced if 100% completion actual - experiment amount percent yield - ratio of actual yield over theoretical yield x100

Question 51

What are 2 ways to increase yield?

Answer 51

start with more reactants | shift equilibrium to right - (remove products as they are formed)

Question 52

How to calculate how much oxygen is needed for combustion

Answer 52

add 1 for each carbon and subtract 0.5 for each oxygen. (this is a ranking system not the exact moles required)

Question 53

Which requires the most oxygen to combust, propane, propanol or propanoic acid?

Answer 53

propane needs most, propanol, and propanoic acid needs most oxygen

Question 54

What is equilibrium?

Answer 54

the state reached in the progress of a reversible reaction where there ceases to be additional NET progress in either forward or reverse direction

Question 55

What is the formula for the law of mass action?

Answer 55

Keq= products/reactants

Question 56

How does addition of a catalyst, increased temp, lowering activation energy, stabilizing the transition state, and addition of reactants/products affect equilibrium?

Answer 56

``` catalyst - no effect increase temp = exothermic rxn- increase Keq. lowering activation energy = no effect stabilizing transition state = no effect adding products/reactants = no effect ```

Question 57

What is the reaction quotient?

Answer 57

calculation of products/reactants taken at any other point than equilibrium

Question 58

If Q>K, the reaction will proceed to the __

Answer 58

left

Question 59

If Q

Answer 59

right

Question 60

What is le chatelier's principle?

Answer 60

systems at equilibrium that experience change will shift left or right to reduce effects of that change and re-establish equilibrium

Question 61

What is the difference between kinetics and thermodynamics?

Answer 61

kinetics - study of reaction rate (how fast reactants disappear) thermodynamics - reflect the potential reactivity (enthalpy, free energy, entropy and Keq)

Question 62

What 2 things must occur for a reaction to start?

Answer 62

1. the reactants must collide with enough energy to overcome the energy of activation 2. the reactants must be in the correct spatial orientation

Question 63

How will increasing reactants, products, catalyst, energy of activation, energy of transition state, energy of reactants , and temperature affect rate of reaction?

Answer 63

inc. reactants = inc rate inc. products = no effect inc. catalyst = inc. rate inc. energy of activation = dec. rate inc. energy of transition state = dec. rate inc. temp = inc. rate

Question 64

the overall order of a reaction=

Answer 64

the sum of the exponents in the rate law

Question 65

How do you calculate the order of each reactant using experimental data?

Answer 65

1. find two trials where reactant in question changed 2. note the factor by which reactant concentration changed 3. note factor by which rate changed across those same 2 trials 4. solve for Y in X^Y = Z. X = factor which reactant changed Y= order Z= factor by which rate changed