Thermal Equilibrium and Diffusion/Effusion
How much energy is required to heat up 80 g of water from 26C to 48C? Give your answer in J.
7.4 x 10^3 J
If 16 J of work is being done on a system and 1016 J of heat are being gained by the surroundings, what is the total change in internal energy of the system?
-1000 J
C + O2 --> CO2 ΔHrxn = -3000kJ
Based on the above information, what is the change in enthalpy for the reaction below?
3CO2 --> 3C + 3O2
+9000 kJ
If I have 4.00 moles of a gas at a pressure of 5.60 atm and a volume of 12.0 liters, what is the temperature?
205K
The distance between two corresponding points on a light wave.
wavelength (λ)
Determine the final temperature when 32.2 g of water at 14.9 °C mixes with 32.2 grams of water at 46.8 °C.
30.9 C
A piston has external pressure of 8.80 atm. How much work has been done if the cylinder goes from volume of 0.550 L to 0.950 L? (101.3 J = 1L*atm). Give your answer in J.
-357 J
Ammonia reacts with oxygen to form nitrogen dioxide and steam, as follows:
4NH3(g) + 7O2(g) ---> 4NO2(g) + 6H2O(g)
Given the following standard enthalpies of formation (given in kJ/mol), calculate the enthalpy of the above reaction:
NH3(g) −45.90kj/mol
NO2(g) +33.1kj/mol
H2O(g) −241.8kj/mol
O2(g) - 0kj/mol
-1135kJ
A cylinder contains 28.5 L of oxygen gas at a pressure of 1.8 atm and a temperature of 298 K. How much gas (in grams) is in the cylinder? (R = 0.08206)
67g
The number of crests that pass a given point per second. Described in units of inverse second (s-1), or hertz (Hz).
Frequency (v)
A 10 g iron bar (temp = 80C) is dropped into 70 g of water (temp = 25C). What is the final temperature? (specific heat of water is 4.184 J/gC, iron is 0.46 J/gC)
26 C
A 7.0 g sample of cyclohexane (MW = 84.1 g/mol) is combusted in a bomb calorimeter with total heat capacity of 3.86 kj/C. The temp of the calorimeter increases from 20.5C to 30.8C. What is the heat combustion for the cyclohexane in kJ/mol? Give answer rounded to three significant figures.
-478 kJ/mol
Find the enthalpy change for this reaction,
{{ 2S + 3O2 → 2SO3 }}
using the enthalpies of other reactions given:
S + O2→ SO2 ∆H = - 297 kJ
2SO3 → 2SO2 + O2 ∆H = 198 kJ
-792 kJ
4NH3(g)+7O2(g)→4NO2(g)+6H2O(l)
According to the above reaction, what volume of NO2(g) is produced from the combustion of 100 g of NH3(g), assuming the reaction takes place at standard temperature and pressure?
132 L NO2(g)
Calculate the wavelength of light that corresponds to a frequency of 9.41 x 1014 per second. Report your answer in units of nanometers.
319nm
What is the molecular weight of a gas which diffuses 1/50 as fast as hydrogen?
5040g/mol
When 0.725g Mn is combined with enough hydrochloric acid to make 102.0mL of solution in a coffee-cup calorimeter, all of the Mn reacts, raising the temperature of the solution from 24.2C to 29.1C. Find the change in enthalpy for the reaction as written. (Assume that the specific heat capacity of the solution is 4.18 J/gC and the density is 1.00 g/mL).
-1.58 x 105 J
The balanced equation for the combustion of C2H6 (ethane) is:
2C2H6(g) + 7O2(g) ---> 4CO2(g) + 6H2O(g)
Using standard enthalpies of formation, calculate the heat of combustion per mole of gaseous water formed during the complete combustion of ethane gas.
The enthalpies of formation needed are:
C2H6(g) -84.68
O2 (g) zero
CO2 (g) -393.5
H2O (g) −241.8
ΔH = -476kJ/mol
A gas is heated from 263.0 K to 298.0 K and the volume is increased from 24.0 liters to 35.0 liters by moving a large piston within a cylinder. If the original pressure was 1.00 atm, what would the final pressure be?
0.777 atm
Determine the longest wavelength of light required to remove an electron from an atom of a metal, if the binding energy for an electron in that metal is 309 kJ/mol. Provide your answer in nm.
387nm
2.278 x 10-4 mol of an unidentified gaseous substance effuses through a tiny hole in 95.70 s. Under identical conditions, 1.738 x 10-4 mol of argon gas takes 81.60 s to effuse. What is the molar mass of the unidentified substance?
31.98g/mol
A balloon of argon gas initially at 2.3 L transfers 485 J of heat to the surroundings. The final volume of the balloon is 2.05 L. The external pressure is 1 atm. What is the total change in internal energy for the system? (101.3 J = 1 atm*L). Give answer rounded to three significant figures.
-460J
Consider the following reaction: 2C4H10 + 13O2 → 8CO2 + 10H2O ΔHrxn = -2044 kJ If we have a 10.8 kg sample of C4H10, calculate heat in kJ for the complete combustion of all C4H10 present. Round to 3 significant figures.
-1.90*10^5 kJ
A 276.58-g sample of X2(g) has a volume of 30.0 L at 3.2 atm and 27°C. What is element X?
Chlorine