Thermo Chemistry
Hand warmers contain iron powder which produces heat when exposed to air:
4Fe(s) + 3O2(g) → 2Fe2O3(s). Which of the following is true about this reaction?
ΔH < 0
A mixture of oxygen and neon has a pressure of 1.031 atm.
If the pressure of the oxygen is 0.922 atm, what is the pressure of the neon?
0.109 atm
kg·m2/s2
What is joules(J)?
Which orbitals resembles the shape of a four leaf clover?
The d orbital
Determine the amount of heat produced when 6.40 mol of N2H4 reacts with O2.
2N2H4(l) + 7O2(g) → 2N2O5(s) + 4H2O(g); ΔH =
-1154 kJ
3690kJ
An open flask sitting in a lab fridge looks empty, but it is actually filled with a mixture of gases called air. If
the flask volume is 5.00 L, and the air is at standard temperature and pressure, how many gaseous molecules
does the flask contain?
1.34x1023
Sodium atoms in fireworks give off yellow light. This is an example of…
light emission
What is the maximum number of electrons in an atom that can have the quantum numbers n=4 ℓ=2?
10
Determine DH°rxn for the complete combustion of 1.00 mol of propane at 25°C and 1 atm.
C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(l)
Standard enthalpy of formation ΔH°ƒ in kJ/mol: C3H8(g) -103.8; CO2(g) -393.5; H2O(l) -285.8
-2220kJ
Use Boyle’s law to calculate the initial pressure of a 485 mL sample of helium gas that has been changed at
constant temperature to 1.16 L and 1.18 atm.
2.82 atm
According to the electromagnetic spectrum, which of the following is incorrect?
a) long radio waves
b) high energy xrays
c) high frequency gamma rays
d) high energy microwaves
e) low frequency radio waves
d) high energy microwaves
For a halogen to become an ion, it needs to gain electrons in which orbital group?
p6
Calculate DH for the condensation of ethanol: C2H6O(g) → C2H6O(l)
2C(s) + 3H2(g) +1/2 O2(g) → C2H6O(g)
ΔH = -235.1 kJ
2C(s) + 3H2(g) +1/2 O2(g) → C2H6O(l)
ΔH = -277.7 kJ
-42.6kJ
Calculate the pressure at which oxygen (32.00) has a density of 1.44 g/L at 22°C.
1.09 atm
What is the wavelength of red-orange light that has an energy of 3.28X10-19 J?
606 nm
How many valence electrons are in the ground state electron configuration 1s22s22p3?
5
A 186 g sample of a metal at 74.0°C is placed in 251 g of water at 18.0°C, and the final temperature
of the systm is 26.4°C. Calculate the specific heat of the metal.
1.00J/g°C
When 1.06 g Hg2O (417.18) is decomposed, the oxygen produced has a pressure of 0.514 atm and a volume
of 62.5 mL at 35.25°C. Calculate the value of R from these data. 2Hg2O(s) → 4Hg(l) + O2(g)
0.08206 Latm/molK
Calculate the kinetic energy of a 1.95 X 105 kg locomotive that is traveling at 43.6 cm/s.
1.85x104 J
[Xe]5d106s1