Chapter 7-9
Calculate the energy change for the reaction of 2 moles of HF to produce 1 mol of H2 and 1 mol of F2 given the average bond energies.2HF → H2 + F2H-H (bond energy: 436 kJ/mol)F-F (bond energy: 155 kJ/mol)H-F (bond energy: 569 kJ/mol)
+547 kJ
What is the mass of zinc sulfide (ZnS) required to produce 18.2 grams of zinc phosphide (Zn3P2) according to the following balanced equation? 3ZnS + 2AlP → Zn3P2 + Al2S3
20.6 grams
Which sample would have the greatest mass in grams?
1 mol Ti
How many moles of calcium (Ca) would be required to react with 2.50 moles of water (H2O) according to the balanced equation below:Ca + 2H2O → Ca(OH)2 + H2
1.25 moles
Which of the following solutions is the LEAST CONCENTRATED?
10 grams of solute in 45 grams of solution
What is the molar mass of Fe(OH)3? (A mol of Fe(OH)3 would have a mass of how many grams?) Hint: This is calculated the same way as formula mass.
106.9 g/mol
Which sample would have the greatest number of atoms?
2 mol Na
How many moles of solute are present in 2.0 L of a solution that has a molarity of 1.50 M?
3.0 moles
How many molecules of sucrose are in 0.380 L of a 1.55 M solution of sucrose?
3.55 x 10^23 molecules
What is the pH of a solution that has a hydronium ion (H3O+) concentration of 2.8 x 10-5 M?
4.55
Which of the following solutions would be considered acidic? Select all that apply, this is a multiple response question.
A solution with pH=3, a solution with [H3O+] = 1.0 x 10-5
Which of the following atoms would be the most polarizable?
Germanium (Ge)
n the chemical equation below, which substances would be considered products? Select all that apply, this is a multiple response question.CH4 + 2O2 → CO2 + 2H2O
CO2, H20
For the acid-base reaction below, identify the other product formed.HF + Ca(OH)2 → H2O + ?????
CaF2
Carbon dioxide reacts with water to form _________.
Carbonic acid
In the destruction of ozone molecules by chlorinated fluorocarbons, the chlorinated fluorocarbons are acting as a(n) ________, by converting hundreds of thousands of ozone molecules (O3) to O2 without being used up.
Catalyst
How readily an acid donates a hydrogen ion is a function of how well the acid is able to accommodate the resulting negative charge it gains after donating. Which should be the stronger acid, HClO4 or HClO2? Why?
HClO4, because the resulting negative charge is spread over a greater number of highly electronegative oxygen atoms.
Which of the following molecules would be capable of hydrogen bonding? Select all that apply, this is a multiple response question
HF, H20, NH3
What is an exothermic reaction?
It is a reaction that generates heat as a product
Choose the correct coefficient for each reactant and product to correctly balance the chemical equation below, the decomposition of potassium chlorate to form potassium chloride and oxygen:___ KClO3 → ___KCl + ___ O2(Note: Canvas does not allow subscripts to appear properly in matching questions in Canvas.)
KCLO3: 2, KCL: 2, O2: 3
Which compound in the acid-base reaction below is acting as a base?KOH + HNO3 → H2O + KNO3
KOH
Why do red blood cells, which contain an aqueous solution of dissolved ions and minerals, burst when placed in fresh water?
More water molecules enter the cell (through osmosis) than leave the cell.
Which of the following are correct statements about solutions? Select all that apply, this is a multiple response question.
Solutions are homogenous mixtures, A saturated solution has the maximum amount of solute that can be dissolved under given conditions, Solutions can be solids, liquids or gases.
Sodium hydroxide (a strong base) is added to a buffer solution of acetic acid (a weak acid) and acetate (a weak base). What is the effect on the concentration of acetic acid? What is the effect on the concentration of acetate?
The concentration of acetic acid decreases, the concentration of acetate increases
Which of the following statements best describes what is happening in a water softening unit?
The hard ions in the water are exchanged for ions like sodium that do not interact as strongly with soaps.
If the pH of a solution decreases from 5 to 3, how did the hydronium ion (H3O+) concentration change?
The hydronium ion concentration increased by a factor of 100.
How does a soap molecule dissolved in water orient itself around a particle of oil?
The nonpolar tail points towards the oil and the polar head points towards the water.
How would an increase in global temperature affect the solubility of carbon dioxide dissolved in ocean water?
The solubility of Carbon dioxide would decrease
The solubility of a given substance in water is 36.0 grams per liter. If 18.0 grams of the substance are dissolved in 0.500 L of water, which of the statements below would best describe the solution?
The solution is saturated