CHEM 105 EXAM 3 ALL ROUND PRACTISE
QUESTIONS TO BE EXPECTED
What is the mass (in mg) of 2.63 moles of nickel - ANSWER: 1.54x10^5
A mass of mercury occupies .750L. What would an equal mass of ethanol occupy?
The density of mercury is 13.546g/ml and the density of ethanol is 0.789g/ml -
ANSWER: 12.9L
Convert 10,000cm3 to m3 - ANSWER: 1x10^-2 m
Which set of Q# contains an error? - ANSWER: n=3
l= 3
ml= =2
All are homogenous mixtures except? - ANSWER: Mud and water
Which quantum number describes the orientation of an orbital? - ANSWER: The
Magnetic Quantum Number (ml)
Calculate the frequency of red light emitted with a wavelength of 700nm - ANSWER:
USE: f= c/wavelength (3.00x10^8)(7x10^-7)
=4.29x10^14
Convert 250F to Celcius - ANSWER: USE: (F-32)*5/9
= 121C
How many moles are in 2.16x10^24 atoms of lead - ANSWER: 3.59 moles Pb
Round the following to 4 sig figs using correct notation - ANSWER: 3.546x10^-1
Convert um to m - ANSWER: u = 10^-6
1x10^-6m
What are the possible orbitals for n=3 - ANSWER: s,p,d
How many orbitals are present when l=3 - ANSWER: TRICK (value of l)(2) +1 when
given the value of l
(3)*(2)+1 = 7 Orbitals present
Determine the number of p, n, e in the element
65
, 29 X - ANSWER: P= 29
E= 29
N= 65-29 = 36
How many orbitals are in the 7th shell - ANSWER: TRICK: When asked about the
shell, square the value
7th shell (7^2) = 49 orbitals in the seventh shell
Gallium has an atomic mass of 69.723.
Ga-69 (68.926)
Ga-X (amu?) - ANSWER: ANSWER: 70.924amu
Remember:
-find missing percent
-change percents to decimals
-Add up the isotopes as set equal to the total atomic mass given
-WATCH YOU NUMBERS
-Do not round until the end the values will be really close for the answer choices
Identify by chemical symbol
18
8 X - ANSWER: Defined by protons
8p = Oxygen
Iodine is an example of - ANSWER: An element
Which orbital on average is closest to the nucleus - ANSWER: 2s
Which species is represented by
p= 47
n= 62
e= 46 (means the element will be positive) - ANSWER: Ag+ (periodic table the
account of charge)
Correct values for 3p sub level - ANSWER: n= 3
l= 1
ml= 0
Calculate the mass in grams of 2.6x10^24 moles of Hg - ANSWER: 6.5X10^2 g
Molecules can be described as - ANSWER: two or more atoms chemically joined
together
When waves of equal amplitude that are OUT OF PHASE interact it is called? -
ANSWER: Destructive Interference
QUESTIONS TO BE EXPECTED
What is the mass (in mg) of 2.63 moles of nickel - ANSWER: 1.54x10^5
A mass of mercury occupies .750L. What would an equal mass of ethanol occupy?
The density of mercury is 13.546g/ml and the density of ethanol is 0.789g/ml -
ANSWER: 12.9L
Convert 10,000cm3 to m3 - ANSWER: 1x10^-2 m
Which set of Q# contains an error? - ANSWER: n=3
l= 3
ml= =2
All are homogenous mixtures except? - ANSWER: Mud and water
Which quantum number describes the orientation of an orbital? - ANSWER: The
Magnetic Quantum Number (ml)
Calculate the frequency of red light emitted with a wavelength of 700nm - ANSWER:
USE: f= c/wavelength (3.00x10^8)(7x10^-7)
=4.29x10^14
Convert 250F to Celcius - ANSWER: USE: (F-32)*5/9
= 121C
How many moles are in 2.16x10^24 atoms of lead - ANSWER: 3.59 moles Pb
Round the following to 4 sig figs using correct notation - ANSWER: 3.546x10^-1
Convert um to m - ANSWER: u = 10^-6
1x10^-6m
What are the possible orbitals for n=3 - ANSWER: s,p,d
How many orbitals are present when l=3 - ANSWER: TRICK (value of l)(2) +1 when
given the value of l
(3)*(2)+1 = 7 Orbitals present
Determine the number of p, n, e in the element
65
, 29 X - ANSWER: P= 29
E= 29
N= 65-29 = 36
How many orbitals are in the 7th shell - ANSWER: TRICK: When asked about the
shell, square the value
7th shell (7^2) = 49 orbitals in the seventh shell
Gallium has an atomic mass of 69.723.
Ga-69 (68.926)
Ga-X (amu?) - ANSWER: ANSWER: 70.924amu
Remember:
-find missing percent
-change percents to decimals
-Add up the isotopes as set equal to the total atomic mass given
-WATCH YOU NUMBERS
-Do not round until the end the values will be really close for the answer choices
Identify by chemical symbol
18
8 X - ANSWER: Defined by protons
8p = Oxygen
Iodine is an example of - ANSWER: An element
Which orbital on average is closest to the nucleus - ANSWER: 2s
Which species is represented by
p= 47
n= 62
e= 46 (means the element will be positive) - ANSWER: Ag+ (periodic table the
account of charge)
Correct values for 3p sub level - ANSWER: n= 3
l= 1
ml= 0
Calculate the mass in grams of 2.6x10^24 moles of Hg - ANSWER: 6.5X10^2 g
Molecules can be described as - ANSWER: two or more atoms chemically joined
together
When waves of equal amplitude that are OUT OF PHASE interact it is called? -
ANSWER: Destructive Interference
