Calorimetry and Heat
What units is heat, q, measured in?
How many protons are in an atom of Sulfur?
16 protons
How many electron domains are around the central atom in methane?
4
If a system's heat changes by +500 J, the heat change of its surroundings must be
-500 J
How many electrons are in a sodium ion?
10 electrons
How many electron domains and bonding domains are around the central atom of a molecule with a trigonal planar geometry?
3 electron domains, all 3 of which are bonding domains.
Equal masses of water and sand left out in the sun. They start out at the same temperature, but by the end of the day the sand is hotter than the water. Explain this phenomenon.
Sand has a lower specific heat than water. The two absorbed the same amount of energy, but the sand is more susceptible to temperature change so ends up hotter
Why is there only one way to write an atom's ground state electron configuration but many ways to write its excited state electron configurations?
Ground state is the lowest energy state, so there is only one configuration possible. Excited states are any energy higher than ground state, so multiple states and therefore configurations exist.
What is the molecular geometry of oxygen difluoride?
Bent
C(s) + 2H2(g) --> CH4(g)
-74.5 kJ/mole CH4
Give the ground state electron configuration of titanium, Z=22, in noble gas configuration
[Ar]4s23d2
What is the approximate bond angle in a molecule of sulfur dioxide?
120°
Calculate the final temperature of 15.0g of water initially at 15.2°C that has lost 489 J of heat. cH2O = 4.184 J/(g°C)
7.4°C
Give the group number of the elements whose electron configuration ends in s2p3
Group 5A (Nitrogen group)
Which of the following molecules is polar?
O2
H2O
CO2
H2O