Potassium nitrate has a delta H solution of +34.9kJ/mol. If you dissolved 10g of this in 100ml of water. What would happen to the temperature of the water?
It would go down (decrease)
100
What is the enthalpy of formation of N2(g)?
0 (it is in elemental form)
100
What color of visible light has the lowest energy per photon?
Red
100
What is the electron configuration notation of a P atom in its ground state?
1s2 2s2 2p6 3s2 3p3
100
Which has the largest atomic radius?
N Al B
Al
200
A fuel is burned in a cylinder with a piston. Delta E for the reaction is known to be -150kJ. If the combustion releases 85kJ of heat, calculate the sign and magnitude of the work done by the piston
- 65kJ
200
What are the two reasons that bond enthalpy calculations often give incorrect values for a delta H of a reaction
- They are average values
- They don't include IMF breaking/forming (they assume all species are gases)
200
How many orbitals are in the f subshell?
7
200
From which subshell are the electrons removed when you form an Sn 2+ ion from an Sn atom?
5p
200
Which has the highest ENC?
Ca 2+ Ar P 3-
Ca 2+
300
How much heat (in J) is needed to increase the temperature of 0.250 L of water by 76 K?
7.9 x 10^4 (79,000) J
300
Which of the following will have the most positive bond enthalpy?
N=N N-N N (triple) N
N (triple) N
300
How many nodal planes does a 3d orbital have?
2 (or two cones for 3d (z squared))
300
How many unpaired electrons does an Fe atom have in its ground state?
4
300
Which element is the most electronegative?
Se P Si
P
400
A coal fired steam engine is 35% efficient. How much heat will be released (in J) by burning coal in order for the engine to do 255 J of work?
474 J
400
If a reaction takes in 100kJ of heat as it takes place, what can be said about the strength of the bonds in the products compared to those in the reactants?
The bonds in the products are weaker / the bonds in the reactants are stronger
400
The n=2 to n=1 transition in a H atom loses more energy than any of the possible relaxations to the n=2 level. What type of photon is emitted by the n=2 to n=1 transition?
A UV photon
400
What would you predict Hf's noble gas electron configuration to be?
[Xe] 6s2 4f14 5d2
400
Which has the highest first ionization energy?
Al Mg K
Mg
500
0.100 moles of a solid solute weighs 20.0g. This is dissolved in 0.100 L of water which starts at 298 K. What will the final temperature of the solution be if the enthalpy of solution of the solute is -100 kJ/mol?
318 K
500
Calculate DH for the following reaction, using DHf data from your data sheets:
2CH3OH(l) + 3O2(g) -> 2CO2(g) + 4H2O(l)
(-1930) - (-476.8) = -1454 kJ/mol
500
How would you expect the kinetic energy of the 1s photoelectron emitted from a F atom in a PES scan to compare to the kinetic energy of a 1s photoelectron from a C atom?
The F atom 1s electron would have a smaller kinetic energy than the C atom 1s electron
500
What is the noble gas configuration for Cr 3+ ?
[Ar] 4s0 3d3
500
Would you expect Se or As to have the highest first ionization energy and WHY?
As. The electron comes from an unpaired orbital which has less e- e- repulsion and is harder to remove