How do you know if something is an isotope?
they have the same atomic number but not necessarily the same atomic mass
If the density of nitrogen in air is 0.870 g/L, what mass (in kg) of nitrogen is contained in a room with dimensions of 13.3 m × 4.58 m × 2.43 m?
129kg
What is the correct answer to the following expression: (765.0 + 36.0) × 0.81150?
650
Express 0.00735 in scientific notation
7.35E-3
What is the percent mass of carbon, hydrogen and oxygen in acrolein, C3H4O?
C 64.26, H 7.2, O 28.54
Which element is most likely to form a 2+ ion?
N Mg Na S Al
Mg
What are the respective coefficients when the equation is balanced with the smallest whole numbers?
__ Al + __ FeO → __ Fe + __Al2O3
2 3 3 1
If 13.0 g N2 and 2.46 g H2 react to produce 1.30 g NH3, what is the percent yield of the reaction?
N2(g) + 3 H2(g) → 2 NH3(g)
9.4
Select the ions present in Ca3(PO4)2
Ca2+ PO4 3-
Which of the following observations is/are examples of chemical change?
1. Sodium chloride melts at 801 0C.
2. The density of water
decreases when it changes from a liquid to a solid.
3. The
combustion of propane gas yields carbon dioxide and water
only 3
Which of the following formulas correctly match the given names?
1. dinitrogen tetroxide, NO4
2. cobalt(II) sulfate,
Co2SO4
3. carbon tetrachloride, CCl4
3
Which of the following are covalent compounds?
1. CO2
2. HBr
3. Al2O3
1 2
Which of the following compounds are named correctly?
1. Ca(NO3)2, calcium(II) nitrate
2. K2CO3, potassium
carbonate
3. Ca(OH)2, calcium hydroxide
2 3
You have 5.67 g of each of the following elements: Na, Ca, Pb, Ti and Zn. Which sample contains the largest number of moles?
Na
A compound containing nitrogen and oxygen is 69.55% by mass oxygen with a molecular weight of 92.02. What is the molecular formula for this compound?
N2O4
How many atoms of fluorine are present in 4.00 moles of NF3?
7.23E24
Which of the following statements concerning atomic structure is/are correct?
1- Neutrons and electrons are found in the nucleus.
2- In a
neutral atom, the positive charge of the protons is balanced by the
negative charge of the neutrons.
3- Electrons are negatively
charged particles and surround the nucleus in the form of an
electronic cloud
3
How many protons, electrons and neutrons are present in 40Ca2+?
20 P 18 e 20 N
Two students independently determine the volume of ethanol delivered
by a 50.00-mL pipet. Each student takes 10 measurements, then
calculates the average volume delivered and the standard deviation.
The results are tabulated below.
AverageSt. Dev. Student
A50.01 mL±0.02 mL Student B51.50 mL±2 mL
Which statement best
describes the results?
A: good precision, good accuracy. B: poor precision, poor accuracy
Iron reacts with oxygen to produce iron(III) oxide.
4 Fe(s) + 3 O2(g) → 2 Fe2O3(s)
If 6.96 moles of Fe react with excess O2, how many moles of Fe2O3 can be formed?
3.48
Which statements below are true about homogeneous mixtures?
1. They have constant composition.
2. They are
uniform throughout.
3. They are composed of pure
substances that are chemically combined
2
Helium has 2 naturally occurring isotopes, He-4 (4.003 u) and He-3 (3.016 u). In an unusual sample of helium taken from a natural gas well the abundance of He-4 is 95.78%. What is the average atomic mass of this sample of helium?
3.961
For the following reaction 0.224 moles of nitrogen are allowed to
react 0.416 moles of hydrogen. What is the limiting reagent and how
much ammonia can be produced?
N2(g) +
3H2(g) 2NH3(g
H2 0.277
Which have the same mass?
1. 5.5 x 10-3 kg
2.
5.5 x 103 g
3. 5.5 x 1012 ng
2 3
What is the ground state electron configuration for P3-?
[Ne]3s23p6
What are the oxidation numbers of sulfur in each of the following compounds SF6, S2F10 and SF4, respectively?
+6 +5 +4
All of the following sets of quantum numbers are allowed EXCEPT
n = 2, l= 0, ml
= +1
n = 3, l= 0, ml = 0
n = 4, l = 2, ml = –1
n = 5, l = 3, ml = +2
n = 2, l = 1, ml = 0
1
What is the ground state electron configuration for F?
[He]2s22p5
If 103 mL of 1.84 M HCl(aq) is diluted with water to a volume of 926 mL, what is the molarity of the diluted HCl(aq)?
.205
The pH of an aqueous HI solution is 4.08. What is the H3O+ concentration of the solution?
8.32E-5
Which of the following are diamagnetic?
1. Li
2.
Mg
3. N
2
If a cordless phone operates at a frequency of 46.7 MHz. What is the wavelength of this radiation?
6.4 m
What is the net ionic equation for the reaction of copper(II) hydroxide and hydrochloric acid?
Cu(OH)2(s)+2H+(aq)Cu2+(aq)+2H2O(l)
Which of the following compounds are soluble in
water?
1. Ca3(PO4)2
2. CuCH3COO
3. CuCO3
4. Cu2S
2
What is the net ionic equation (NIE) for the reaction of aqueous sodium bromide and aqueous lead(II) nitrate?
Pb+2(aq)+ 2Br-(aq) PbBr2(s)
What is the mass of potassium iodide in 112 mL of 4.61E-2 M KI(aq)?
.857
For a hydrogen atom, calculate the wavelength of an
emitted photon in the Lyman series that results from the transition
n = 6.00 to n =
1.00. Rydberg constant is 1.097E+7
m–1.
(h = 6.626E-34 J×s and c = 2.998E+8 m/s)
93.8 nm
What is the net ionic equation for the reaction of potassium hydroxide and hydroiodic acid?
H+(aq)+OH-(aq)H2O(l)
What is the ground state electron configuration for Co2+?
[Ar]sd7
Which species in the below reaction is the reducing agent?
Zn(s)+ 2Ag+(aq)Zn2+(aq)+ 2Ag(s)
Zn(s)
Which of the following sets of quantum numbers refers to a 3p orbital?
n=3, l=1, ml=-1
Which of the following statements about the atomic structure model
is/are correct?
1- According to quantum theory, electrons
are in orbits around the nucleus at quantized energy levels.
2-
Rutherford's experiment proved that most of the atom is empty space,
and the protons are in the nucleus.
3- According to quantum
theory, electrons are in an electronic cloud around the nucleus
2 3
A 21.46 mL sample of NaOH is titrated with 27.78 mL of 0.1591 M HCl(aq). What is the concentration of the NaOH solution
.2060
What is the net ionic equation (NIE) for the reaction of aqueous ammonium sulfide and aqueous calcium nitrate?
Ca2+(aq)+ S2-(aq) CaS(s)
What are the spectator ions in the reaction between aqueous ZnCl2 and aqueous K3PO4?
K+ Cl-
What is the ground state electron configuration for Si?
[Ne] 3s2 3p2
R
1.097E-7
h
6.626E-39
c
2.998E-10
average atomic mass
(% abundance/100)* mass plus any additional
# orbitals in shell
n2
# orbitals in subshell
2L+1
Aufbau
lower levels filled first
Pauli
only 2 e- per orbitals with opposite spins
Hund
singly occupied before doubling up
Long Wavelengths vs short wavelengths
long wavelength -> low frequency, low energy, short line
short wavelength -> high frequency, high energy, long line
formal charge
valence e- - (LPE + 1/2 BE)
how many particles/atoms in 1 mole
6.022E23
bond order trend
single is longest and weakest
triple is strongest but shortest
atomic radius trend
increases going down and decreases going right
Exothermic
Expansion
system working ON surroundings
H < 0 q < 0 w< 0
surroundings get warmer
Endothermic
Compression
surroundings effect system
H > 0 q > 0 w > 0
surroundings get colder