Acid Base:
A solution is prepared by adding 100 mL of 1.0 M NH3 (ap) to 100 mL of 1.0 M NH4Cl (aq). The solution is stirred and its pH is measured to be 9.26. After 3 drops of 1.0 M HCl are added to the solution, the pH of the soltuion is measured and Is still 9.26. Which of the following equations represents the chemical reaction that accounts for the fact that acid was added but there was no detectable change in the pH?
B. H+(aq) + NH3(aq) --> NH4+(aq)
Based on the information above, which of the following species will be present in a 1.0M H2CO3 solution a the lowest concentration?
CO3^-2
FR14- A. Write a balanced chemical equation for the dissolution of Ca(OH)2 (s) is pure water.
Ca(OH)2 --> Ca+2 + 2OH-
FR- A IN the box below, complete a particle representation diagram that includes four water molecules with proper orientation around the Ca+2 ion.
DRAW IT idk what to tell you
FR13- D. Assume that the initial concentration of the HA solution (before any NaOH solution was added) is 0.200M. Determine the pH of the initial HA soltuion.
HA + H2O --> H3O+ + A- .2M X 0 0 -x X +x +x ,2-x x x
FR13- E. Calculate the value of [H3O+] in the solution after 30.0 mL of NaOH is added and the total volume of the solution is 80.0mL.
HA + OH- --> A- + H2O .01 .0075 +.0075 -.0075 -.0075 = .0025/.08 = .0075/.08 = .0313M = .0938M HA + H2O --> H3O + A- .0313M 0 .0938M -x +x +x .0313-x x .0938+x (6.3X10^-5)= (x)(.0938)/(.0313) x= (2.10X10^-5)
FR14 - B. Calculate the molar solubility of Ca(OH)2 in 0.1 M Ca(NO3)2.
Ksp: [Ca+2][OH-]^2 Ca(OH) ---> Ca^+2 + 2OH- X 0 0 +x +2x X 2x (1.3X10^-6)=(x)(2x)^2 (1.3X10^-6=4x^3
11. At point Q in the titration, which of the following species has the highest concentration?
• A. HA
Which of the four acids list in the table is hydrobromic acid?
• A. acid 1
The concentration of HA is closest to which of the following?
• B. 0.80 M
Which of the following statements best explains the experimental findings about the strength of the acid, HA?
• B. HA is a weak acid, as s evidence by the PH>7 at the equivalence point.
12. At which point on the titration curve is [A-] closest to being equal to that of [HA]?
• B. S
For which acid is the value of the acid dissociation constant, Ka, the smallest?
• B. acid 2
Of the following species, which has he greatest concentration in a 1.0 M solution of Acid 2 at equilibrium?
• C. acid 2
when 300 mL of 1.0 M NaOH is added to 200 mL of 1.0 mL of 1.0 M Hcl (aq), the pH of the resulting mixture is closest to
• D. 13.0
if equal volumes of the four avids at a concentration of 1.00 M are each titrated with a strong base, which will require the greatest volume of base to reach the equivalence point?
• D. all of the acids will require the same volume of base to reach the equivalence point.
FR13- B Write the balanced net-ionic equation for the reaction that occurs when the solution of NaOH is added to the solution of HA.
• HA(aq) + OH- (aq) --> A- (aq) + H2O (l)
FR13- C. calculate the concentration of the HA solution
• M = mols/L M=.01mols/.05L M=.2M
A 25 mL sample of a 1.0 M solution of acid 1 is mixed with 25 mL of 0.50 M NaOH. What do you expect the pH to be of the resulting solution?
• PH<7
FR13 - A Explain how the data in the table above provide evidence that HA is a weak acid rather than a strong acid?
• We are told equivalence point is 40.0mL of NaOH is added. The table shows we have a pH of 8.26 at this point meaning the pH is above 7 so we have a strong base and weak acid.
