Chemistry Midterm Review
Sulfuric acid may be produced by the following process: 4FeS2 +11O2 > 2Fe2O3 + 8SO2 2SO2 + O2 > 2SO3 SO3 + H2O > H2SO4 How many moles of H2SO4 will be produced from 8.41 moles of FeS2?
16.8
Calculate the work associated with the expansion of a gas from 42.0 L to 79.0 L at a constant pressure of 14.0 atm
-518 L atm
The average mass of a carbon atom is 12.011. What are the chances that you would randomly pick a carbon atom with a mass of 12.011
0%
Diabetics often need injections of insulin to help maintain the proper blood glucose levels in their bodies. How many moles of insulin are needed to make up 45 mL of 0.0062 M insulin solution?
0.00028 mol
A scientist obtains the number 0.045006700 on a calculator. If this number actually has four (4) significant figures, how should it be written?
0.04501
You measure water in 2 containers: a 10 mL graduated cylinder with marks every mL and a 1 mL pipet marked at every 0.1 mL. If you add the water together, to what decimal could you report the total volume of water?
0.1 mL
Given reaction N2 + 3H2 -> 2NH3 you mix 1 mol each of nitrogen and hydrogen gases under the same conditions in a container fitted with a piston. Calculate the ratio of volumes of the container (Vfinal/Vinitial)
0.67
Express the volume 781.2 cm^3 in liters
0.7812 L
What is the subscript of barium in the formula of barium sulfate?
1
What is the specific heat capacity of a metal if it requires 178.1 J to change the temp of 15.0 g of the metal from 25 degrees C to 32 degrees C
1.70 J/gC
What is the best answer to report for [(3.478 g x 1.164 g)/2.00] - 0.169 g/mL?
1.85 g/mL
How many of the following postulates of Dalton's atomic theory are still scientifically accepted? I. All atoms of the same element are identical. II. Compounds are combinations of different atoms. III. A chemical reaction changes the way atoms are grouped together. IV. Atoms are indestructible.
2 (II and III are still accepted)
The valve between the 2.00L bulb, in which the Gas pressure is 1.80 atm,& the 3.00 L Bulb,in which the Gas pressure is 3.00 atm, is opened. What is the final pressure in the two bulbs, the temperature remaining constant?
2.52 atm
A sample of chemical X is found to contain 5.0 grams of Oxygen, 10.0 grams of carbon and 20 grams of nitrogen. The law of definite proportion would predict that a 70 gram sample of chemical X should contain how many grams of carbon?
20 grams
A chunk of lead at 91.6°C was added to 200.0 g of water at 15.5°C. The specific heat of lead is 0.129 J/g°C, and the specific heat of water is 4.18 J/g°C. When the temperature stabilized, the temperature of the mixture was 17.9°C. Assuming no heat was lost to the surroundings, what was the mass of lead added?
211 g
Calculate the molar mass of barium sulfite
217.40 g/mol
30.0 mL of pure water at 282 K is mixed with 50.0 mL of pure water at 306 K. What is the final temperature of the mixture
297 K
the ΔH value for the reaction 1/2O2(g) + Hg(l) -> HgO is -90.8 kJ. How much heat is released when 66.9 g Hg is reacted with oxygen?
30.3 kJ
Bromine exists naturally as a mixture of bromine-79 and bromine-81 isotopes. An atom of bromine-79 contains
35 protons, 44 neutrons, and 35 electrons
The net ionic equation for the reaction of calcium bromide and sodium phosphate contains which of the following species?
3Ca+2(aq)
A sample of oxygen gas has a volume of 1.72 L at 27.2 degrees C and 800 torr. How many Oxygen molecules does it contain
4.43 x 10^22
A gaseous mixture containing 1.5 mol Ar and 3.5 mol CO2 as a total pressure of 7.3 atm. What is the partial pressure of CO2?
5.1 atm
How many grams of NaCl are contained in 350 mL of a 0.287 mL of 0.287 M solution of sodium chloride?
5.87 g
Suppose the reaction Ca3(PO4)2 + 3H2SO4 -> 3CaSO4 + 2H3PO4 is carried out starting with 153 g of Ca3(PO4)2 and 76.8 g of H2SO4. How much phosphoric acid will be produced?
51.1 g
6.1 seconds contains this many picoseconds
6.1 x 10^12
A hypothetical element consists of 2 isotopes of masses 69.95 amu and 71.95 amu with abundances of 25.7% and 74.3% respectively. What is the average atomic mass of this element
71.4 amu
Express 0.0810 in scientific notation
8.10 x 10^-2
How many grams of potassium are in 27.8 g of K2CrO7>
8.98 g
Which of the following names is incorrect
aluminum (III) oxide
Which of the following statements are true of uranium-238? 1) Its chemical properties will be exactly like those of uranium-235. 2) Its mass will be slightly different from that of an atom of uranium-235. 3) It will contain a different number of protons than an atom of uranium-235 4) It is more plentiful in nature than uranium-235
Statements 1,2, & 4
When a water molecule forms a hydrogen bond with another water molecule, which atoms are involved in the interaction?
an hydrogen from one molecule and an oxygen from the other molecule
Consider the following containers, one with helium at 27 degrees C and the other with aragon at the same temp. Which of the following statements is true?
The average kinetic energy of the two samples are equal.
Which of the following statements is correct?
The internal energy of a system increased when more work is done by the system than heat was flowing into the system.
Which of the following is the least probably concerning 5 measurements taken in the lab?
The measurements are accurate but not precise.
Electron configuration for Cu
[Ar]4s^1 3d^10
Which of the following pairs can be used to illustrate the law of multiple proportions? a) SO and SO2 b) CO and CaCO3 c) H2O and C12H22O11 d) H2SO4 and H2S e) KCl and KClO2
a) SO and SO2
All of the following are characteristics of nonmetals except: -poor conductors of electricity -often bond to each other by forming covalent bonds - tend to form negative ions in chemical reactions with metals - appear in the upper left hand corner of the periodic table - do not have a shiny (lustrous) appearance
appear in the upper left hand corner of the periodic table
All of the following are postulates of the KMT of gases except
at a constant temperature each molecule has the same kinetic energy
Avogadro's hypothesis states that
at the same temperature and pressure, equal volumes of different gases contain an equal number of particles
All of the following are true except: a) ions are formed by adding electrons to a neutral atom b) Ions are formed by changing the number of protons in an atom's nucleus c) ions are formed by removing electrons from a neutral atom d) an ion has a positive or negative charge e) metals tend to form positive ions
b) Ions are formed by changing the number of protons in an atom's nucleus
Molecular structure of H2O
bent
The bonds between hydrogen and oxygen within a water molecule can be characterized as
intramolecular forces
Atoms with greatly different electronegativity values are expected to form
ionic bonds
The correct name for FeO is
iron (II) oxide
Molecular structure of CO2
linear
Metals typically have _ electronegativity values
low
the specific heat capacities of metals are relatively _
low
Order the 4 metric prefixes from smallest to largest
nano<milli<centi<kilo
A point in the wave function where the amplitude is zero defines the
node
The four lines observed in the visible emission spectrum of hydrogen tell us that
only certain energies are allowed for the electron in the hydrogen atom
In the reaction P4(s) + 10Cl2 (g) -> 4PCl5(s) the reducing agent is
phosphorus
Electromagnetic radiation can be thought of as a stream of particles called
photons
The boiling of water is a
physical change because the gaseous water is chemically the same as the liquid
The following reactions are examples of ZnBr2(aq) + 2AgNO3 (aq) -> Zn(NO3)2(aq) + 2AgBr(s) KBr(aq) + AgNO3(aq) -> AgBr(s) + KNO3(aq)
precipitation reactions
As part of the calibration of a new laboratory balance, a 1.000-g mass is weighed with the following results: 1.201+-0.001, 1.202+-0.001, 1.200+-0.001. The balance is
precise but inaccurate
Energy can only occur in discrete units called
quanta
Which form of electromagnetic radiation has the longest wavelengths?
radio waves
More protons = _ radius
smaller
which of the following is not an assumption of the kinetic molecular theory for a gas
the average velocity of the gas particles is directly proportional to the absolute temperature.
Dalton's law of partial pressure states that
the total pressure of a mixture of a mixture of gases is the sum of the partial pressure of all the gaseous compounds
Which metals form cations with varying positive charges?
transition metals
Which one of the following types of radiation has the shortest wavelength, the greatest energy, AND the highest frequency? a) Ultraviolet Radiation b) Infrared Radiation c) Visible Red Light d) Visible Blue Light e) None because short wavelength is associated with low energy and low frequency, not high energy and high frequency
ultraviolet radiation
Electromagnetic radiation exhbits
wave properties
Intermolecular forces are _ than intramolecular bonds.
weaker
If a student performs an endothermic reaction in a calorimeter how does the calculated value of ΔH differ from the actual of the heat exchanged with the calorimeter is not taken into account?
ΔHcalc would be less positive because the reaction absorbs heat from the calorimeter
Which of the following is true about the kinetic molecular theory
Pressure is due to the collisions of the gas particles with the walls of the container
Which bond is most polar?
Si-F
All of the following are in an aqueous solution. Which is incorrectly named?
HCN- cyanic acid
Which of the following bonds would be the least polar, yet still be considered polar covalent
N-O
Which substance involves no bonding forces except London dispersion forces?
N2
In which of the following does iodine have the lowest oxidation state?
NH4I
the more moles of a gas, the _ volume
higher
Which of the following atoms would have the largest second ionization energy a) Mg b) Cl c) S d) Ca e) Na
Na
Which of the following species is best described by drawing resonance structures
O3
P1/T1 =
P2/T2
P1V1T2 =
P2V2T1
Ideal Gas Law
PV=nRT
Which of the following is not a postulate of the kinetic molecular theory? A. Gas particles have most of their mass concentrated in the nucleus of the atom. B. The moving particles undergo perfectly elastic collisions with the walls of the container. C. The forces of attraction and repulsion between the particles are insignificant. D. The average kinetic energy of the particles is directly proportional to the absolute temperature. E. All of the above are postulates of the kinetic molecular theory.
A. Gas particles have most of their mass concentrated in the nucleus of the atom.
Which of the following groups from the periodic table would be the easiest to oxidize a) halogens b) transition metals c) transuranic d) alkali metals e) alkali earth metals
Alkali metals
Of the following elements, which has the lowest first ionization energy? (Ba, Ca, Si, P, Cl)
Ba
Ionization energy of bromine
Br(g) -> Br+(g) + e-
Which of the following bonds is least polar?
Br-Br
Adipic acid contains 49.32% C, 43.84% O and 6.85% H by mass. What is the empirical formula?
C3H5O2
When 0.72 g of a liquid is vaporized at 110 degrees C and 0.967 atm, the gas occupies a volume of .558 L. The empirical formula of the gas is CH2. What is the molecular formula of the gas?
C3H6
For which compound does 0.256 mole weigh 12.8 g?
CH3Cl
Based on electronegativities, would you expect to be most ionic?
CaF2
In Bohr's atomic theory when an electron moves from one energy level to another energy level more distant from the nucleus
Energy is absorbed
Consider 2 organic molecules, ethanol and benzene. One dissolves in water and the other does not. Why?
Ethanol contains a polar O-H bond, and benzene does not.
A 45.9 g sample of a metal is heated to 95.2 degrees C and then placed in a calorimeter containing 120.0 of water at 21.6 degrees C. The final temp of the water is 24.5 degrees C. Which metal was used?
Iron (c=0.45 J/gc)
The density of gasoline is 0.7025 g/mL at 20 degrees C. When gasoline is added to water
It will float on top
Use the kinetic molecular theory of gases to predict what would happen to a closed sample of a gas whose temperature increased while its volume decreased.
Its pressure would increase
Which of the following is soluble in water?
K3PO4
In which pair do both compounds exhibit predominantly ionic bonding
LiBr and MgO
the important of the equation E=mc^2 is that
energy has mass
