Final Exam Flashcards
Which of the following defines a hypothesis?
A hypothesis is a tentatively accepted explanation of the facts.
Why is Antoine Lavoisier considered by some to be the “father” of chemistry?
He was the first to apply quantitative measurements to a chemical problem. He weighed out the reactants and the products of a chemical reaction before and after the reaction. What he learned became the law of conservation of matter.
“Melting point” is not a(n) _____________________.
qualitative property of a substance
Calcium carbonate is a compound that can decompose into carbon dioxide and calcium oxide. Carbon dioxide, in turn, is made up of the elements carbon and oxygen. What needs to happen to a compound in order for it to be broken down into either elements or simpler compounds?
The compound needs to undergo a chemical reaction.
How many neutrons are in the nucleus of an atom of calcium-43?
23
A new stable element with an atomic number of 120 and an atomic mass of 246 is created in a particle accelerator. Enough of this element is created to determine that it combines with chlorine in a 1:2 ratio. Element 120 should be placed in the same group as _____ on the periodic table.
beryllium (Be)
What is the coefficient for water in the properly balanced equation for the combustion of butane and oxygen gas to form carbon dioxide gas and water according to the equation:
C4H10 + O2 → CO2 + H2O
10
What are the conversion factors that would be used to determine the number of atoms of oxygen in 0.23 moles of silver nitrate (AgNO3 )?
A reaction has an expected yield of 30.5 grams. What is the percent yield if performing the reaction produced 29.6 grams of product?
97.0 percent
The following reaction is of which type?
2KClO3(s) —> 2KCl(s) + 3O2(g)
oxidation-reduction reaction
If 145.0 mL of 0.350 M lithium hydroxide is required to titrate 35.0 mL of an unknown monoprotic acid, what is the molar concentration of the unknown acid?
1.45 M
A 2.32 L balloon contains helium at 1.00 atm and 25°C. How many grams of helium are contained in the balloon?
0.380 g He
What is the root-mean-square speed (urms) in m/s for ethane (C2H6) at 298 K?
R = 8.314 J/(mol•K), and 1 J = 1 kg•m2/s2.
497 m/s
What are the two ways that energy can be transferred between the system and the surroundings?
work and heat
The molar heat of neutralization of a strong acid and a strong base is determined by mixing 50.0 mL of 1.0 M HCl with 50.0 mL of 1.1 M NaOH in a coffee cup calorimeter. The initial temperatures of two solutions was 25.32°C and the final temperature inside the calorimeter was 31.43°C. What is the molar heat of neutralization? Assume that the specific heat capacity of the solution is identical to water and the density is 1.00 g / mL.
−51.6 kJ / mol
When filling multiple orbitals that have the same energy (called degenerate orbitals), two electrons are placed in different orbitals rather than paired in a single orbital. This is an example of which of the following?
Hund’s rule
Moving accross a row in the periodic table from left to right, which of the following quantities increases?
electron affinity and ionization energy
In the following chemical reaction, what is being reduced?
2K(s) + 2H2O(l) —> H2(g) + 2K+(aq) + 2OH-(aq)
water molecule
The electron configuration for vanadium is 1s22s22p63s23p64s23d3.
How many valence electrons does vanadium have?
5
Which of the following is the correct Lewis dot structure of nitric acid, HNO3?
Which of the following shows (in the correct order) the oxidation numbers for phosphorous (P) and oxygen (O) in the polyatomic ion PO43−?
+5, −2
Which of the following does not play a role in determining when a phase change occurs?
the amount of compound
What is a saturated solution?
A saturated solution is a solution that contains the maximum possible concentration of solute (at a given temperature).
A certain type of sugar dissolves in water, but the solution created does not conduct electricity. Therefore, the sugar does not form ions when dissolved in solution. When 10.0 g of this sugar are dissolved in 25.0 g of water, the freezing point of the solution is −5.0°C. If the freezing point depression constant for water (Kf) is 1.86°C/m, what is the molar mass of the sugar?
150 g/mol
A _____ is a gas dispersed in a liquid.
foam
Using the following data for the reaction 2NO2(g) + F2(g) → 2FNO2(g)
what are the values of m, n, and k in the rate law rate = k[ NO2 ]m [ F2 ]n?
m = 1, n = 1, k = 1.6 M −1s−1
Which of the following expresses the half-life for a first-order reaction?
t1/2 = In 2/ k
In the Arrhenius equation the “A” is:
the frequency factor
For many reactions involving enzymes (E) reacting with substrates (S) to form products (P), steady state approximations can be applied to derive the rate law:
Which of the following shows the rate law when the concentration of substrate is very large in relation to the k values?
rate = kobs[E]0
Which reaction shown below involves a heterogeneous catalyst?
2NO(g) ——-> N2(g) + O2(g)
If the value of the equilibrium constant with regard to concentration (Kc ) is found to be 2.54 × 106 at 30°C, what is the value of the eqilibrium constant with regard to pressure?
(R = 0.0821 L • atm / mol • K)
PCl3(g) + Cl2(g) PCl5(g)
1.02 × 105
In the following equation for the dissociation of sulfuric acid in water, identify the conjugate bases.
H2SO4(aq) + H2O(l) —> HSO4-(aq) + H3O+(aq)
HSO4- and H2O
What is the pH of a 0.10 M solution of the weak base methylamine (NH2CH3 )?
(Kb = 4.4 × 10−4 )
11.82
Consider the following reaction between nitrous and ammonia:
HNO2(aq) + NH3(aq) NH4NO2(aq)
Ka = 4.5 x 10^-4 Kb = 1.8 x 10^-5
What is the equilibrium constant for this reaction?
8.1 × 10^5
The value for Kf for Ag(NH3)2+ is 1.7 × 107. What is the dissociation constant for this complex ion?
5.9 x 10–8
Which acid contains the most electronegative halogen?
hydrofluoric acid
Considering hybridization effects, which of these organic compounds must be the strongest acid?
The alkyne
What happens when a bond is broken heterolytically?
One atom gets a pair of electrons.
Refer to the potential energy diagram below. Which of the following statements concerning this reaction is TRUE?
This reaction is reversible.
What is entropy?
a thermodynamic quantity that is a measure of the randomness or disorder in a system
At what temperature does ΔH = TΔS for the phase change of liquid water to gaseous water at 1 atm?
373 K
Which of the following is the properly balanced equation for the reaction of nitrous acid and iodide ion?
HNO2(aq) + I-1(aq) —> NO(g) + I2(s)
2H+(aq) + 2HNO2(aq) + 2 I-2(aq) —> 2NO(g) + 2H2O(l) + I2(s)
Manganese can be found in many oxidation states. Which of the following is the strongest oxidant?
MnO4−, MnO2, MnCl2, Mn
MnO4−
All of the following batteries use zinc metal at the anode except I. lead storage battery II. Leclanché dry cell battery III. alkaline battery IV. mercury battery V. lithium battery
I and V only
In the formation of rust in aerobic conditions, what is the role of the iron metal?
anode and conduit for electrons
Which of the following is produced at the cathode of an electrolytic cell containing a 1.0 M solution of sodium chloride?
hydrogen gas
The energy gap between the valence band and the conduction band in silicon is 100 kJ/mol. The energy gap for germanium will be:
smaller
Which of the following compounds cannot exist?
Na(OH)2
What is the complimentary DNA strand for the following sequence?
T–T–C–G–A–C–G–A
A–A–G–C–T–G–C–T
Which of the following shows the alcohol called ethanol?
