Unit 1
Give an example of an element that is a metal and an element that is a nonmetal.
Metal - anything on the left or in the center.
Nonmetal - anything on the right.
What is the molar mass of MgCl2?
95.2 g
What is a saturated solution?
A solution that has as much stuff dissolved in it as possible. There may be undissolved product at the bottom of the container.
Calculate the delta E of a system in which 200 kJ of heat is absorbed from the surroundings while the system does 175 kJ of work.
200 - 175 = 25 kJ
Write the complete electron configuration for Phosphorus.
1s2 2s2 2p6 3s2 3p3
What separation technique would be used to separate a solid substance from a liquid substance?
Filtration
A sample of C3H8O that contains 200 molecules contains _______ carbon atoms.
200 x 3 = 600
Explain the difference between a strong, weak, and nonelectrolyte.
Strong electrolyte fully dissociates into its ions in water. Weak electrolytes partially dissociate, and nonelectrolytes don't dissociate.
Describe what is happening to heat in an endothermic and exothermic reaction.
Heat is absorbed in an endothermic reaction and released in an exothermic reaction.
How many total valence electrons are in the compound BF3?
24
What is the name of NaClO2?
Sodium Chlorite
How many moles are in 150 g of NH3?
8.82 mol
Predict the products of the reaction below and balance it.
__ Fe(NO3)2 + __ KOH -->
Fe(NO3)2 + 2 KOH --> Fe(OH)2 + 2 KNO3
2 Mg + O2 --> 2 MgO Delta H = -1204 kJ
Calculate the amount of heat transferred when 5 g of Mg reacts.
-123.8 kJ
Which atom has a larger ionization energy and why? Ga or Se? Don't just talk about location on the periodic table.
Se has the larger ionization energy because it is a smaller atom that holds onto its electrons tighter than Ga. Therefore it requires more energy to remove its electrons.
How many protons, neutrons and electrons are in the isotope Magnesium - 27?
Protons = 12
Electrons = 12
Neutrons = 27 - 12 = 15
Balance the reaction below.
__ C3H6 + __ O2 --> __ CO2 + __ H2O
2, 9, 6, 6
Identify which element is oxidized and which element is reduced in the reaction below.
Fe2O3 + 3 CO --> 2 Fe + 3 CO2
C is oxidized from +2 to +4
Fe is reduced from +3 to 0
How many kJ of heat are needed to raise the temperature of 500 g of liquid water from 25 degrees Celsius to 80 degrees Celsius. The specific heat of water is 4.18 J/g-K.
114.95 kJ
When would you expect to see a large jump in ionization energy values for Aluminum? Between the 1st and 2nd, 2nd and 3rd, or 3rd and 4th? Why?
Between the 3rd and 4th because the 4th electron is being removed from a shell that is closer to the nucleus.
Explain what a mass spectrum graph looks like and how you would interpret it to determine what element it is representing.
A mass spectrum is a graph with peaks at every isotope mass of an element. The height of the peak represents the abundance of that isotope. Average the peak masses to determine the element.
How many sulfur atoms are in 3.25 g of S2O3?
3.4 x 1022 S atoms
Calculate the molarity of a solution made by dissolving 5.65 g of NaOH in enough water to form 500 mL of solution.
0.28 M
When a 15.00 g sample of sodium hydroxide dissolves in 100.00 g of water in a coffee cup calorimeter, the temperature rises from 25 degrees to 45 degrees. Calculate delta H (in kJ/mol NaOH) for the solution process. The specific heat of the solution is 4.18 J/g-K. Molar mass of NaOH is 40.00 g.
-25.6 kJ/mol NaOH
Which compound has the higher lattice energy and why? NaF or KF?
NaF has the higher lattice energy because Na is smaller than K. They both have the same amount of charge, so we look to size. Smaller atoms have a stronger attraction to one another.