General Questions and Answers
Physical Chemistry
GeneralWhat is the final temperature when 10.0 grams of water at 25.0 °C absorbs 50.0 calories of heat energy? specific heat of water = 1.00 cal/g °C)
20.0 °C
23.8 °C
30.0 °C
50.0 °C
Physical Chemistry
GeneralThe number of atoms in 0.50 mole of Br₂ is approximately
1.5x10²9
3.0x10²3
6.0x10²3
12x1023
Physical Chemistry
GeneralArrange the elements according to first ionization energy.
Highest ionization energy
Lowest ionization energy
Ge
C
Sn
Si
Physical Chemistry
GeneralA measurement of the mass of an object was made three times and gave values of 9.6g, 9.8g, and 10.3g. What is the best value to report as the mass, in grams, of this object?
9.7
9.8
9.9
10.0
Physical Chemistry
GeneralThree grams of a salt were dissolved in 2 liters of water. In order to make 5 liters of a solution of the same concentration, how many grams of salt must be used?
3.3
6.0
7.5
15
Physical Chemistry
GeneralWhat is the molar mass (molecular weight) of the compound C₂H4O₂?
29
32
44
60
Physical Chemistry
GeneralWhat is the symbol of the atom with the electron configuration 1s²2s²2p6 3s²3p3?
N
O
P
S
Physical Chemistry
GeneralAt 298 K, the Henry's Law constant for oxygen is 0.00130M/atm. Air is 21.0% oxygent.
A. At 298 K, what is the solubility of oxygen in water exposed to air in 1.00atm?
B. At 298K, what is the solubility of oxygen in water exposed to air at 0.892atm?
C. If atmospheris pressure suddenly changes from 1.00 atm to 0.892 atm at 298 K, how much oxygen will be released from 5.40 L of water
in an unsealed container?
Reminder: M = kHP
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Physical Chemistry
GeneralWhich neutral atom has six valence electrons?
Mg (atomic number 12)
Si (atomic number 14)
P (atomic number 15)
S (atomic number 16)
Physical Chemistry
GeneralWrite the net ionic equation for the reaction of lead(II) nitrate and sodium iodide.
Pb(NO)3(aq) + 2Nal(aq) --> Pbl₂(s) + 2NaNO₂(aq)
Pb²+(aq) + 2Nal(aq) → Pbl₂(s) + 2Na(aq)
Pb²+(aq) + 2I- (aq) → Pbl₂(s)
Pb²+(aq) + 2I¯(aq) → Pb²+(s) + 2I- (aq)
Physical Chemistry
GeneralYou have three solutions of nickel complex ions: one is blue, one is violet, and one is green. Match the complex ion with the
correct solution color.
Blue
[Ni(en)]2+
Violet
[Ni(H₂O)]²+
Answer Bank
Green
[Ni(NH3)6]2+
Physical Chemistry
GeneralAs a substance was heated, the intermolecular forces could no longer hold molecules rigidly together, and the molecules began to move randomly in relation to one another. Which
statement most accurately describes what happened to this substance?
It changed from a solid to a liquid
It changed from a liquid to a solid
It changed from a gas to a liquid
It changed from a liquid to agas
Physical Chemistry
Generalconsider the following balanced equation.
Mg₂N₂(s) + 6 H₂O(l) → 3 Mg(OH)2 (s) + 2 NH3(g)
When 100.g Mg3N₂ reacts with 75.0 g H₂O, 15.0g of NH3 is obtained.
Which of the following is the limiting reactant?
Mg3N2
Mg(OH)₂
NH₂
Physical Chemistry
GeneralHow many moles of nitrate ions are present in 1.0L of a 0.02M AI(NO3)3 solution?
0.02
0.03
0.06
0.08
Physical Chemistry
GeneralHow many grams of NaOH (MW = 40g) are present in 0.200 L of 0.25 M solution?
0.05
2
10
50
Physical Chemistry
GeneralIf you have not yet used your data to make a solubility curve graph, look at the graph provided in the video and Identify the label of the vertical (y) axis and the label of the horizontal (x) axis)
Physical Chemistry
General70. The only natural abundances of Boron are B-10 with a mass of 10.013 amu, and B-11 with a
mass of 11.009 amu. What are their abundances?
Physical Chemistry
GeneralSoap molecules have a polar "head" and a non-polar "tail". How does that help explain why soap is so good at cleaning dirty clothes?
Physical Chemistry
GeneralThe distance a car skidded during an accident was measured in two parts and found to be 273.15 cm + 21 cm. The total distance should be reported as
294 cm
294.15 cm
294.2 cm
290 cm
Physical Chemistry
GeneralGroups of elements have similar
atomic mass
number of isotopes
physical properties
valence electrons
Physical Chemistry
GeneralGiven 35CI-, the correct values of protons, neutron and electrons are
17 protons, 18 neutrons, 18 electrons
17 protons, 17 neutrons, 17 electrons
17 protons, 16 neutrons, 18 electrons
18 protons, 17 neutrons, 16 electrons
Physical Chemistry
GeneralCalculate the molarity of NaCl in a 0.550 m solution of NaCl in water. Assume that the solution density is 1.03 g/mL.
Physical Chemistry
GeneralHow can you tell if you are calculating a mole problem; a stoichiometry problem?
Physical Chemistry
GeneralUse the following balanced equation to answer the following problems:
C5H12 + 8O2 5CO2 + 6H₂O
i) When 2.5 moles of oxygen gas react completely with pentane, how many moles of
carbon dioxide are produced?
ii) How many grams of pentane gas are needed to completely react with 348.5 grams of
oxygen?
Physical Chemistry
GeneralMagnesium has 3 naturally occurring isotopes: Magnesium-24, Magnesium-25, and
Magnesium-26. They have masses 23.985042 amu, 24.985837 amu, and 25.982593 amu,
respectively. If 78.99% of all Magnesium is Magnesium-24, what are the abundances of
Magnesium-25 and Magnesium-26?
Physical Chemistry
General1 mol = 22.4 L 1 mol = 6.02 x 1023 representative particles 1 mol = g (molar mass)
30. Know how to perform mole conversions using moles, grams, and representative particles.
a. What is a representative particle? What is the name of the representative particle for the
ionic compound? The covalent compound? An element?
b. How many representative particles are in a 53.79 gram sample of SrCO3?
C. How many moles of AlF3 are in a 10.0 gram sample of AlF3?
d. How many grams of SO₂ are in a 0.65 mole sample of SO₂?
e. How many moles of copper atoms in 75 g of Cu?
f. In a sample with 17.0 grams of water, how many molecules of water are present?
Physical Chemistry
GeneralCompare and contrast the behavior of an electrolyte solution and a non-electrolyte solution.
Physical Chemistry
GeneralA burner was designed to use LPG whose volumetric composition is propane 60%
and butane 40%, currently this burner must use C.N. (methane 100%). Find the
diameter ratio between the NG injector and the fuel injector. LPG if you want to keep
constant the power in the burner and the pressure of feed is the same for both gases.
Physical Chemistry
GeneralWrite out the proper formulas of the reactants, predict the products, when necessary, for the
reaction, balance the reaction and identify the type of reaction. If the reaction is single replacement
tell if the reaction is going to happen.
a. silver chlorate reacts with lithium to produce......
Physical Chemistry
GeneralClassify each of the following particulate level illustrations as a representation of either a pure substance or a mixture.
pure substance
mixture
Physical Chemistry
GeneralWhen calcium reacts with fluorine to form an ionic compound, each metal atom loses _ electron(s) and each nonmetal atom gains _ electron(s).
There must be _ calcium atom(s) for every _ fluorine atom(s) in the reaction.
Physical Chemistry
GeneralExplain how you would make 1.5 L Copper (1) sulfate solution that is 2.0M.
V
Physical Chemistry
Generalb. Zinc nitrite reacts with potassium phosphate to create.......
C. Tetracarbon decahydride reacts with oxygen to produce carbon dioxide and water
d. Iron (III) hydroxide when heated creates iron (III) oxide and water
e. Magnesium metal reacts with chlorine to produce magnesium chloride
f. NaNO3 + CaCO3 →
g. Au + CuCl2 →
Physical Chemistry
GeneralA _ spectrometer can also be used to
study in detail about the composition of a
certain material based on its emitted spectral
lines.
prism
photo
absorption
emission
Physical Chemistry
GeneralFePO4 + Na₂SO4 → Fe₂(SO4)3 + Na3PO4
a. Suppose that Joey ran the reaction above with 25 grams of FePO4 and excess Na₂SO4. What is
the theoretical yield of Fe₂(SO4)3 that will be produced?
b. If 18.5 g Fe₂(SO4)3 are produced, what is the percent yield?
c. Suppose that Bobby runs the same reaction and produces 16 g of Fe₂(SO4)3. Who did a better
job running the experiment? Explain.
Physical Chemistry
General1. If 20.0 grams of magnesium react with 15.0 grams hydrochloric acid, how many grams of
magnesium chloride are produced?
2. How many grams of carbon dioxide are produced if 45.0 grams of sodium hydrogen
carbonate reacts with 40.0 grams of acetic acid?
Physical Chemistry
GeneralA solution of 3.6 g of NaOH (a strong base) is added to enough water to create a volume of 2.6 L
a. What is the pOH of the solution?
b. What is the pH of the solution?
c. Using the ion product concentration of water (Kw) determine the hydronium ion concentration of this solution?
Physical Chemistry
GeneralDraw Lewis dot structures for these simple compounds listed below.
i. Br2
ii. O2
iii. N₂
iv. CH4
V. NH3
vi. H₂O
vii. HF
Physical Chemistry
GeneralIf 144g of carbon and 12g of hydrogen gas are
fully reacted, what mass of benzene (C6H6) will
form?
6C(s) + 3H2(g) --> C6H6)
276g
132g
78g
68g
156g
Physical Chemistry
GeneralWhat amount of heat energy would be necessary to raise the temperature of 100 g of
water at room temperature (25°C) to the boiling point (100°C)? The specific heat of
water is 1.0 cal/g °C.
7500 cal
750 cal
100 cal
75 cal
Physical Chemistry
GeneralComplete and balance the following neutralization reactions
HBr + Ca(OH)₂
H3PO4 + Mg(OH)₂
Physical Chemistry
GeneralUndergoing moderate activity, an average
person will generate about 350 kJ of heat
per hour. Using the heat of combustion of
palmitic acid
(ΔH= -9977.6 kJ/mol)
as an approximate value for fatty
substances, estimate how many grams of
fat would be required per day to sustain
this level, if all were burned for heat.
Physical Chemistry
GeneralIf a person has 629mL of a 4.2M KCI solution.
How many moles of KCI would be in the solution?
(1000mL=1L) Round to two decimal places.
Physical Chemistry
GeneralSuppose you are using phenolphthalein as an indicator for a titration. You start with a flask of
base and add the phenolphthalein. Then you add acid until the endpoint is reached.
What color is the indicator in the base?
What color are you looking for to indicate the endpoint?
Explain why a titration is useful:
Physical Chemistry
GeneralHow much heat is absorbed by 2.50 x 102 g of water and the 450. g Al can (CA1 is 0.900 J/g °C) when they are heated from 10.0 °C to 85.0 °C? (ans. 1.09 x 105 J)
Physical Chemistry
GeneralYou have 45.6 mL of 10.1 M HBr. You need to use Mg(OH)2 to neutralize it. How many grams
of Mg(OH)2 are necessary?
Step 1: (a) Write the chemical reaction. (b) Check the subscripts for each new compound.
(c) Balance the equation (check the big numbers in front of each compound).
Step 2: Determine how many moles of HBr you have. (Hint: M = moles/liter)
Step 3: Use the chemical reaction (recipe) to determine how many moles of Mg(OH)2 you need.
Step 4: Use the Periodic Table to determine how many grams of Mg(OH)2 you need.
Physical Chemistry
GeneralWhich of the following are exothermic processes?
1. Combustion of methane
2. Explosion of T.N.T
3. Fusion
4. Melting
2 and 4
2 and 3
1 and 4
Physical Chemistry
GeneralIdentify the incorrect statement from the following.
Increase in temperature, increases the rate of the reaction
Stirring decreases the frequency of interaction between the reactants
Increase in surface of the reactants, increases the rate of the reaction
Increase in pressure of the reactants, increases the rate of the reaction
Physical Chemistry
GeneralThe burning of 5.08 g benzene (C6H6) releases enough heat to raise the temperature of 5.0 kg of water from 10.1 °C to 19.6 °C. Calculate the molar heat of combustion of benzene. (ans.: -3.1 x 103 kJ/mol C6H6)