Chapter 7
Given the following 2 reactions
N2(g)+O2(g)-->2NO(g) (delta)H=180kJ
2NO(g)+O2(g)-->2NO2(g) (delta)H= -112kJ
Calculate the enthalpy change
68 kJ
A colbalt-60 nuclus has a mass of 59.919007 amu. What is the mass defect in amu? The mass of a protron is 1.00728 amu and mass of a neutron 1.00866 amu.
0.5633 amu
A hydrogen atom "relaxes electronically" to the ground state by photon emission. A technician measures the photon wavelength as 380 nm. What's wrong with this alleged result?
Corresponding energy too large
What is the valence electron configuration of a halogen atom
bonus: what is the valence eletron configuration of the free ion that is commonly formed by the halogens
ns2np5
Bonus: ns2np6
How many unpaired electrons are in the ground state electron configuration of a neutral chromium
6
The heats of reaction for sulfur conversion to an oxide are given below:
S(s)+O2(g)-->SO2(g) -296 kJ
S(s) + 3/2O2(g)--> SO3(g) -395 kJ
What is the heat of the reaction for conversion of one mole of SO2 to SO3
-99 kJ
What is the nuclear binding energy of colbalt-60?
8.4186 x 10-11 J
What is the velocity of an electron that has a de Broglie wavelength of 1 cm.
7.28 x 10-2 m/s
What is the ground state electron configuration for Ni?
1s22s22p63s23p64s23d8
or
[Ar]3d8
Identify what is oxidized, what is reduced, the oxidizing agent, and the reducing agent in the following reaction:
Sn + 4HNO3 + 4HCl + 2NaCl-->Na2SnCl6 + 4NO2 + 4H2O
Oxidized: Sn
Reduced: N
Oxidizing agent: HNO
Reducing agent: Sn
Two blocks are placed in thermal contact. One block is aluminum (specific heat=0.90 j/g*K) with a mass 200 g. With an initial temperature of 80.0 C. The second block is iron (specific heat=0.450 j/g*K) an initial temperature of 40.0 C. What is the final temperature after thermal equilibrium is achieved
72 C
A sample of thorium-232 decays via the following squence of emissions: a, B, B, a. What is the product at the end of these four decays?
Radium-224
Find the energy of light with wavelength of 520 nm
3.8 x 10-19
The electron configuration, 1s22s22p63p1, could represent which of the following
Excited state configuration of Na+
Arrange the following in order of increasing wavelength and increasing energy:
infrared, radio waves, green light, yellow light
wavelength: green light < yellow light < infrared < radio waves
energy: Radio < infared < yellow light < green light
When placed in a calorimeter and allowed to equilibrate, a piece of iron (specific heat=0.450 J/g*K) at 45.5 C warms the surrounding 100 g of water (initially at room temperature 25.0 C) to 27.2 C. What is the enthalpy change associated with the same piece of iron if it is used in the following reaction with excess carbon dioxide under standard state conditions (water: 4.184 J/g*K)
-112. kJ
Tritium has a half-life of 12.3 years. How long does it take for a 48. g sample to decay to 6.0 g?
37 years
Suppose a material has a work function equal to 1.7 x 10-19 J. What is the threshold wavelength for the production of photoelectrons.
1.2 x 10-6 m
Identify a cation that is isoelectronic with Ar and is not an alkali metal.
Ca2+
An unknown nuclide decays by one alpha decay, followed by 2 successive beta decays to produce a second nuclide. Bombarding this second nuclide with a 4He nucleus produces the single nuclide product, 159Gd. The original unknown nuclide was...
161Dy
suppose 12.0 L each of nitrogen and hydrogen (initially at 300 K and 1.00 atm) are reacted as fully as possible to form ammonia at the same temperature and pressure. If the heat of formation of gaseous ammonia is -46.1 kJ/mol, how much heat was evolved by the reaction
15 kJ
How much energy is released when a mole of cobalt-60 undergoes beta decay? The mass of the colbalt-60 nucleus is 59.91007 amu and of the nickle-60 nucleus is 59.915428 amu. The mass of an electron is 0.00054858 amu.
6027Co-->0-1e+6028Ni
-2.724*1011
Find the momentum of light with a wavelength of 520 nm.
1.3 x 10-27 kg*m/s
The configuration, [Ar]4s23d4, likely corresponds to the neutral ground state atom of...
none it is an anomalous configuration
A student determined the mass of her unknown solid (12.04 g), placed in a glass test tube heated the tube in boiling water for several minutes the carefully transferred the solid into 75.0 g of water in a coffee cup calorimeter. The temerature of the water increased from 23.3 C to 24.9 C. Assuming heat was gained by the water, what is the identity of the solid?
Platinum: 0.130
Silver: 0.230
Titanium: 0.590
Aluminum: 0.910
Titanimum