Thermochemistry
What is the first law of thermodynamics in algebraic form?
ΔE = q +w
How many protons, neutrons, and electrons does the following isotope have:
18O3-
Protons: 8
Neutrons: 10
Electrons: 11
Fudge contains about 11 g of fat per 100. g of fudge, and fat has a fuel value of 38 kJ per gram, how many kJ does a 200.0 g serving of fudge have from fat?
836 kJ
What is the molar ratio between Cu2S and SO2 in the following reaction:
Cu2S(s) + O2(g) -> 2Cu(s) + SO2(g)
1 mol : 1 mol
Gasoline in a car makes a car engine very hot and is used to move the pistons. Does the gasoline have a positive or negative change of enthalpy? Change of energy?
Negative for both
What is the molar mass of the following substances:
Fe(Cl(ClO3)2)2
459.53 g/mol
How many molecules are in 3.000 mg of iron(II) oxide?
2.515 x 1019 molecules
The combustion of octane (the main component of gasoline) occurs with 96.0% efficiency:
2C8H18(g) + 25O2(g) -> 16CO2(g) + 18H2O(g)
If this reaction is calculated to produce 45.0 kg of CO2, how many kg can we expect to actually form?
43.2 kg
A + B -> C ΔH = +4
E -> C + D ΔH = +7
B + E -> F ΔH = + 10.
B + D + E -> F ΔH = +3
What is:
A + B -> E
+4 J
What is the percent composition of oxygen in the following compound:
KBrO4
34.971%
A beautiful, shining, and sparkling fresh Golden Delicious apple contains 16.0 g of fructose per 120.0 g of apple. If fructose contains 2812 kJ of energy per mol, and fructose's molar mass is 180.156 g/mol, how many colories from fructose does a 250.0 g golden delicious apple have?
520.3 kJ
What is the limiting reactant when 35 mol of FeS and 60.0 mol react via the following reaction:
4FeS + 7O2 -> 2Fe2O3 + 4SO2
O2!
Using appendix C on the handout, calculate the change of enthalpy in the following reaction:
__RbCl(s) + __Ni(g) -> __NiCl2(s) + __Rb(g)
+297.6 kJ
What is the empirical formula of a compound with a molecular weight of 112 amu and the following percent composition:
42.84% C 49.96% N 7.191 % H
C4N4H8
Diamonds are measured in carats and 1 carat = 0.200 g. The density of diamond is 3.51 g/cm3 . A diamond is dropped into a graduated cylinder filled with 30 mL of water and the final volume is measured to be 35 mL. How many carats is the diamond?
88 carats
What is concentration made by diluting 50.0 mL of a 12.5 M solution of hydrochloric acid to 750.0 mL?
0.833 M
Rocket fuel combusts according to the following equation:
__CH6N2(l) + __O2(g) -> __N2(g) + __CO2(g) + __H2O(l) ΔH = - 2,690 kJ
How many kg of fuel is needed to release 1,000,000,000. kJ of heat via this reaction?
34,300 kg
Balance the following equation:
__Fe2O3(s) + __CO(g) -> __Fe(s) + __CO2(g)
1Fe2O3(s) + 3CO(g) -> 2Fe(s) + 3CO2(g)
On the faraway planet Molybdenum VI, concentration is measured in Zons (Z), which is Plips (Pl) per Grosk (Gr). If 12.00 M = 3.45 Z, and they both measure to be 1.50 Gr, how many mol is one Pl?
0.431 mol = 1 Pl
How many g of sulfur dioxide is formed when 100.0 g of FeS and 100.0 g of O2 are combined via the following reaction:
87.9 g/mol 31.998 g/mol 159.687 g/mol
4FeS + 7O2 -> 2Fe2O3 + 4SO2
72.9 g