Ans U 149


A system absorbs 159 kJ of heat, and performs 89 kJ of work on the surroundings. What is Δ of the system?
A) 248 kJ
B) –248 kJ
C) 70 kJ
D) –70 kJ
E) 1.8 kJ
A 1.0 kg block of ice, at 0.0 Celsius is added to a picnic cooler. How much heat will the ice removes as it melts into water at 0.0 Celsius?
A) 80.00 kcal
B) 80,000 kcal
C) 91,000 kcal
D) 19.1 J
On a hot Kansas day the mercury can really rise. A couple of days ago the thermometer read 98oF, what would a Kelvin thermometer have read?
A) 40 K
B) 273 K
C) 310 K
D) 400 K
Express 3.27x105J in kilocalories.
A) 1.37×106 kcal
B) 7.82×104 kcal
C) 78.2 kcal
D) 327 kcal
E) 1.37×103 kcal
How much energy will be needed to heat 69.7 gal of water from 22.0°C to 110.0°C? (Note that 1.00 gal weighs 3.77 kg and that water has a specific heat capacity of 4.184 J/g•°C.)
A) 9.67×107 kJ
B) 2.57×104 kJ
C) 2.57×107 kJ
D) 2.31x104kJ
E) 9.67x104kJ
Consider the following standard heats of formation:
H3PO4(s) = -1279 kJ/mol
P4O10(s) = -3110 kJ/mol
H2O(l) = -286 kJ/mol
Calculate the change in enthalpy for the following process:
4H3PO4(s) → P4O10(s) + 6H2O(l)
A) 290 kJ
B) –290 kJ
C) –2117 kJ
D) 2117 kJ
E) –9942 kJ
True or false? Enthalpy is not a state function.
A) True
B) False
Heat transfer from one solid to another takes place via?
A) Convection
B) Conduction
C) Radiation
D) B and C
E) All of the above
Heat is typically measured in
A) °C
B) °F
C) joules
D) grams
____ is a measure of disorder or randomness.
A) Entropy
B) Enthalpy
C) Calorimetry
D) Internal energy
E) Hess’s law
On the Celsius scale
A) 0 degrees means there is no temperature
B) 80 degrees has twice the heat as 40 degrees
C) the numbers are set by the freezing and boiling point of water
D) none of the above
Which of the following processes is endothermic?
A) water droplets condensing on a soda can on a hot summer day
B) an ice pack getting cold (due to ammonium nitrate dissolving in water inside the pack)
C) thermite reaction between iron(III) oxide and aluminum (spectacular flames are observed)
D) freezing water to make ice cubes
E) none of the above are endothermic processes
True or false? The law of conservation of energy states that energy can be converted from one form to another but can be neither created nor destroyed.
A) True
B) False
The specific heat capacity of iron is 0.45 J/g•°C. How many joules of energy are needed to warm 1.31 g of iron from 20.00°C to 29.00°C?
A) 17 J
B) 12 J
C) 26 J
D) 11 J
E) 5.3 J
561.2 J of heat was added to 8.00 g of water. The final temperature of the water was measured to be 64.2°C. What was the initial temperature of the water? (specific heat capacity of water = 4.184 J/g°C)
A) –81.0°C
B) 81.0°C
C) 47.4°C
D) 3.61°C
E) –5.95°C
Consider the following reaction:
ClF + F2 → ClF3 ΔH = -108.7 kJ/mol
Is the reaction exothermic or endothermic?
A) exothermic
B) endothermic
Perform the indicated conversion: 1.345 kcal  ____ J
A) 5.627×103 J
B) 5.627 J
C) 5.627×10-3 J
D) 321.5 J
E) 3.111 J
In the equationΔE = q + w , the q represents
A) work
B) change in energy
C) moles of a substance
D) mass of a substance
E) heat
Consider the following standard heats of formation:
CO2(g) = -393.5 kJ/mol
PbO(s) = -151.6 kJ/mol
CO(g) = -110.5 kJ/mol
Calculate the change in enthalpy for the following process:
Pb(s) + CO2(g) → PbO(s) + CO(g)
A) 0 kJ
B) –655.6 kJ
C) 655.6 kJ
D) –131.4 kJ
E) 131.4 kJ
For the reaction
H2(g) + 1/2 O2(g) → H2O(l) ΔH = -286 kJ/mol
Calculate the enthalpy change when 4.73 g of hydrogen gas is reacted with excess oxygen.
A) –60.5 kJ
B) 671 kJ
C) –671 kJ
D) 1.35×103 kJ
E) –-1.35x103kJ
How many electrons are in the third principal energy level (n = 3) of one atom of cobalt?
A) 15
B) 13
C) 7
D) 9
E) 18
The energy levels of the hydrogen atom (and all atoms) are ____, meaning that only certain discrete energy levels are allowed.
A) quantized
B) varied
C) ramp-like
D) continuous
E) two of these
As the principal energy level increases in an atom’s orbitals, the average distance of an electron energy level from the nucleus ____.
A) increases
B) decreases
C) stays the same
D) varies
E) none of these
The electron configuration for the sulfur atom is
A) 1s22s22p63s23p4
B) 1s22s22p63s23p6
C) 1s22s22p63s23p2
D) 1s22s22p63s6
E) none of these
True or false? The p block of elements contains the transition metals.
A) True
B) False
The form of EMR (electromagnetic radiation) that has more energy per photon than ultraviolet rays but less energy per photon than gamma rays is
A) microwaves
B) radio waves
C) X rays
D) infrared rays
E) none of these
What element has the electron configuration 1s22s22p63s23p6?
A) He
B) Ne
C) Ar
D) Kr
E) Xe
When an electron in the ground state absorbs energy, it goes to a(n) ____ state.
A) excited
B) lower
C) frenetic
D) ionic
E) stable
How many d electrons are in an atom of cobalt?
A) 7
B) 9
C) 10
D) 27
E) 59
The elements chlorine and iodine have similar chemical properties because they
A) are both metals
B) are in the same chemical period
C) have the same number of electrons in their outer energy levels
D) have the same number of stable isotopes
E) none of these
A given set of d orbitals consists of ____ orbital(s).
A) 1
B) 3
C) 5
D) 6
E) none of these
True or false? The frequency of the wave indicates how many wave peaks pass a certain point per given time period.
A) True
B) False
The number of d orbitals in the second principal energy level is
A) 2
B) 6
C) 10
D) 14
E) none of these
True or false? The speed of a wave indicates how fast a given peak travels through the medium.
A) True
B) False
1s22s22p63s23p64s23d7 is the electron configuration for which of the following atoms?
A) Co
B) Ca
C) Ar
D) Mn
E) Ni
Which of the following is the highest energy orbital for a silicon atom?
A) 1s
B) 2s
C) 3s
D) 3p
E) 3d
The form of EMR that has less energy per photon than infrared rays but more energy per photon than radio waves is
A) microwaves
B) ultraviolet
C) gamma rays
D) X rays
E) none of these
True or false? The 47th electron of silver, Ag, will be in a d orbital
A) True
B) False
The maximum number of electrons in the second principal energy level of an atom is
A) 2
B) 6
C) 8
D) 18
E) 26