What pressure will 2.6x10^23 molecules of H2 exert in a 3.9 L container at 318K
What is 2.9 atm
100
Calculate the change in internal energy of a system giving off 45.0 kJ of heat and is preforming 855 J of work on the surroundings.
What is -45.9 kJ
100
Which of these wavelengths of light has the lowest energy?
10 m 254 nm 680 nm 1x10^-10 m
What is 10 m
100
What is the density of CO2 gas at STP; mm= 44g/mol
What is 1.96 g/L
100
A 25.0 g piece of iron (c=.449 J/g C) at 398 K is placed in a calorimeter containing 25.0 g of water (c=4.184) at 298 K. Assuming no heat is lost to the cup or the surroundings. what is the final temp of the water?
What is 308K
200
Which of the following samples will have the greatest volume at STP?
a. 22g CO d. 22g Cl2
b. 22g He
c. 22g O2
What is b 22g He
200
Which substance would have the smallest increase in temperature when heat is added to it?
a. 50.0 g gold; c=0.129 d. 50.0 g cement; c=0.88
b. 50.0 g water; c=4.184 e. 50.0 g ethylene glycol; 2.42
c. 50.0 g iron; c=0.449
What is b. water
200
Which of the following occur as the energy of a photon increases?
a. frequency decreases d. wavelength gets shorter
b. speed increases
c. deBroglie wavelength increases
What is d. wavelength gets shorter
200
Which of the following transitions in a hydrogen atom represent emission of longest wavelength photon?
a. 1 to 2 d. 4 to 2
b. 3 to 1 e. 5 to 4
c. 3 to 4
What is e. 5 to 4
200
A mixture of N2, O2, and Ar have mole fractions of 0.25, 0.65 and 0.10 respectively. The total pressure of the mixture is 3.9 atm. How many molecules of N2 are present if the sample volume is 5.0 L and the temperature is 300 K?
What is 1.19 x 10^23
300
which of the following statements is True?
a. Particles of different masses have the same average speed at a given temperature.
b. The larger a molecule, the faster it will effuse.
c. The higher the temperature the lower the average kinetic energy of the sample.
d. At a given temperature, lighter gas particles travel more slowly than heavier gas particles.
e. None of these statements are true.
What is e. None of these statements are true.
300
How much energy is evolved during the formation of 98.7 g Fe, from the thermite reaction below?
Fe2O3 + 2 Al --> Al2O3 + 2 Fe Hrxn=-852 kJ
What is 753 kJ
300
Determine the energy change associated with the transition from n=2 to n=5 for a hydrogen atom.
What is 4.58 x 10^-19 J
300
How much energy (in kJ) is required to ionize 2.78 moles of hydrogen atoms?
What is 3.65 x 10^3 kJ
300
Which of the following reactions represents the delta H formation for Ca(NO3)2?
a. Ca(s) + N2(g) + 3O2(g) --> Ca(NO3)2
b. Ca(s) + 2N(g) +6O (g) --->Ca(NO3)2
c. 2 Ca(s) + 2N2(g) + 6O2(g)---> 2 Ca(NO3)2
What is a. Ca(s) + N2(g) + 3O2(g) --> Ca(NO3)2
400
Determine the mass of H2O formed when 12.5 L NH3 (298 K and 1.5 atm) reacts with 18.9 L O2 (323K and 1.1 atm) by the following balanced equation.
4NH3+5O2-->4 NO + 6H20
What is 16.9 grams
400
When 50.0 mL of 1.00 M Ba(NO3)2 solution at 25.0 C is mixed with 50.0 mL of 1.00 M Na2SO4 solution at 25.0 C in a calorimeter (ccal= 9.2 J/C) the temperature of the mixture increases to 28.1 C what is the H rxn in units of kJ/mol Ba(NO3)2? assume the specific heat capacity and the density of the solution are the same as that of water.
What is -26.5 kJ/mol
400
choose the one set of quantum numbers that does not contain an error.
a. n=2,l=2,ml=-1
b. n=2,l=0,ml=-1
c. n=3,l=2,ml=-3
d. n=4,l=3,ml=-2
What is d. n=4,l=3,ml=-2
400
A gas sample initially occupies 35.8L at 1.90 atm and 32.0C. Determine the final temperature of the gas if its pressure and volume have changed to 2.80 atm and 49.6 L.
What is 623 K
400
According to the following balanced thermochemical equation, what volume (in L) of chlorine gas must react at STP to produce 799kJ of heat energy?
P4+6Cl2--->4PCl3 H=-1279 kJ
What is 84.0L
500
Rank the following ions in order of decreasing ionization energy.
Li2+ C5+ F8+