Exam 1
Exam 2
Exam 3
Exam 4
100
45.7 x 0.034 = ?
(use the correct number of sig figs)
1.6
100
What is the molecular geometry of NH3?
trigonal pyramidal
100
Balance the following reaction:
Fe(s) + H2SO2(aq) --> H2(g) + Fe2(SO2)3(aq)
2Fe(s) + 3H2SO2(aq) --> 3H2(g) + Fe2(SO4)3(aq)
100
A 2.0 M cell is placed in a 5.0 M solution. What will happen to the cell?
Crenation
200
Which atom has the smallest radius?
Na, Si, Cl, K
Cl
200
Is NH3 a polar molecule?
Yes
200
Is this reaction endothermic or exothermic?
exothermic
200
Calculate the grams of solute needed to prepare 300 mL of a 4.00 M HCl solution.
43.75g solute
300
What is the electron configuration of Selenium?
[Ar] 3d¹⁰ 4s² 4p⁴
300
If the amount of radioactive iodine-123, used to treat thyroid cancer, in a sample decreases from 2.4 to 0.6 mg in 30.0 h, what is the half-life of iodine-123?
15.0 hours
300
In the following reaction, which element is reduced?
CO(g) + 3H2(g) --> CH4(g) + H2O(g)
Carbon
300
Do reaction rate and activation energy have a direct or inverse relationship?
Inverse
400
In liposuction, a doctor removes fat deposits from a person’s body. If body fat has a density of 0.909 g/mL and 3.0 L of fat is removed, how many pounds of fat were removed from the patient?
6.0 lb
400
What is the formula for the molecule lead (IV) bromide?
PbBr4
400
If 50 g of CS is produced in the lab when 40.0 g of C reacts, what is the percent yield?
Fe2S3(s)+3C(s)→2Fe(s)+3CS(g)
34.0%
400
For the reaction below, what will happen if the pressure is decreased?
2NO (g) + 2H2 (g) ↔ N2(g) + 2H2O(g) + heat
Equilibrium will shift toward reactants
500
Calculate the kilojoules needed to melt 40.0 g of ice at 0 ∘C, warm the liquid to 100 ∘C and change it to steam at 100 ∘C. Express your answer to three significant figures and include the appropriate units.
120. kJ
500
Fluorine-19 is a positron emitter used in PET scans. Write a balanced nuclear equation for the reaction.
19/9 F --> 0/+1 e + 19/8 O
500
What is the pressure (in atm) of 0.156 moles O2 at 25 degrees C in a 6.0L balloon?
0.636 atm
500
A solution of 0.250 M KOH is used to titrate 30.0 mL of a 0.18 M H3PO4 solution. What volume, in milliliters, of the KOH solution is required?
H3PO4 + 3KOH --> 3H2O + K3PO4
64.8 mL