Percent Concentration
A saline solution with a mass of 355 g has 36.5 g of NaCl dissolved in it. What is the mass/mass percent concentration of the solution?
10.3%
What is the concentration (molarity) of a solution of NaCl if 40. mL of a 2.5 M NaCl solution is diluted to a total volume of 500. mL?
0.20 M NaCl
Name the compound and determine if it is soluble or insoluble : AgI
Silver Iodide ; Insoluble
What is the criteria for a reactive collision to occur?
Particles must have a collision with enough energy and the correct orientation.
What is the purpose of buffers?
How do you calculate the pH of buffers?
They are used to maintain constant pH despite outside changes occurring, when there are equal amounts of acid and conjugate base.
Buffer pH is calculated with the Henderson-Hasselbalch equation
If I make a solution by adding water to 75 mL of ethanol until the total volume of the solution is 375 mL, what’s the percent by volume of ethanol in the solution?
20% v/v
A stock solution of 1.00 M NaCl is available. How many mL are needed to make 100.0 mL of 0.750 M
75.0 mL
Name the compound and determine if it is soluble or insoluble : ZnSO4
Zinc Sulfate ; Soluble
How does a catalyst affect a chemical reaction?
A catalyst is part of the reaction that lowers the activation energy, making the reaction occur faster.
What would be the pH of a 100.0 mL solution containing 0.24 M formic acid (HCHO2, Ka = 1.8X10^-4), and 0.24 M sodium formate (NaCHO2).
pH = 3.74
What is the amount (in g) of hydrogen peroxide (H2O2) needed to make a 6.00 kg, 3.00 % (by mass) H2O2 solution?
180 g H2O2
25.5 grams of Lead (IV) Fluoride in 0.088 L would have what molarity?
1.02 M
Please complete the following reaction, and show the complete ionic and net ionic forms of the equation: BeI2(aq) + Cu2SO4(aq) -->
Total Ionic: Be 2+ (aq) + 2 I ¯ (aq) 2 Cu 1+ (aq) + SO4 2- (aq) --> Be 2+ (aq) + SO4 2- (aq) + 2 CuI (s)
Net Ionic: Cu2+ (aq) + I ¯ (aq) --> CuI (s)
Label the diagram (show on slides)
Reactants
Products
Activation Energy
Delta H
90 mL of 0.25 M Ca(OH)2 are required to titrate 100 mL of HCl. What is the molarity of the HCl?
0.45 M HCl
A dextrose (also called D-glucose, C6H12O6) solution with a mass of 2.00 × 10^2 g has 15.8 g of dextrose dissolved in it. What is the mass/mass percent concentration of the solution?
7.90%
What is the concentration of a solution that with a volume 6653 mL that contains 33.4 grams of aluminum acetate?
0.02 M
Name the compound and determine if it is soluble or insoluble : NH4C2H3O2
Ammonium Acetate ; Soluble
In general terms, describe the direction of the equilibrium shift when the concentration of a reactant is increased.
The reaction will shift right, towards the products.
50 mL of a 0.45 M Sr(OH)2 solution is required to titrate a 0.75 M H2SO4 sample. What is the volume (in mL) of the H2SO4?
30 mL H2SO4
Brass is a copper-zinc alloy. If the concentration of zinc is relatively low, the brass has a golden color and is often used for inexpensive jewelery. If a 35.0 g pendant contains 1.7 g of zinc, what is the percentage mass by mass of zinc in brass?
4.9%
Suppose you have just received a shipment of sodium carbonate, Na2CO3. You weigh out 50.00 g of the material, dissolve it in water, and dilute the solution to 1.000 L. You remove 10.00 mL from the solution and dilute it to 50.00 mL. By measuring the amount of a second substance that reacts with Na2CO3, you determine that the concentration of sodium carbonate in the diluted solution is 0.0890 M. Calculate the percentage of Na2CO3 in the original batch of material.
94.3%
Give the net ionic equation for the following : manganese(II)chloride(aq) + ammonium carbonate(aq) --> manganese(II)carbonate(s) + ammonium chloride(aq)
Net : Mn 2+ (aq) + CO3 2- (aq) --> MnCO3 (s)
Consider : 2H2 + O2 --> 2H2O + energy
What happens to the concentrations of the reactants when the reactions shifts the right?
Concentrations decrease
What type of reaction does a titration involve? Neutralization reaction
Neutralization reaction