1. Which answer is a true statement about pH values? a. A high pH value correspo
ID: 586988 • Letter: 1
Question
1. Which answer is a true statement about pH values?
a. A high pH value corresponds to a high H+ concentration
b. Stomach acid has a high pH value.
c. none of the above.
d. Pure water has a pH value of 0.
e. pH is important in life mainly because it effects many everyday applications.
2. The industrial smoke from factories has led to acid rain,which has lowered the pH of a number of lakes having a pH of approximately 5.0. What is the hydronium ion concentration of these lakes ?
a. 5.0 M
b. 10-5 M
c. 105 M
d. log 5.0 M
e. 5.0 %
3. A fish tank containing a number of exotic fish needs a pH of 5.0 , an indicator indicates the pH of the tank is 7.0. What should be done to the hydrogen ion concentration to set the tank to the correct pH.
a. cut it in half.
b. reduce it to 1/100 of its present value.
c. double it.
d. raise it 200 times its present value.
e. raise it 100 times its present value.
4. At 25oC, a sample of milk of magnesia, used as an antacid, has a pH of 10.50. What is the [OH-] in this solution?
a. 3.2 x 10-11 M
b. 2.8 x 10-5 M
c. 3.2 x 103 M
d. 3.0 x 10-2 M
e. 3.2 x 10-4 M
5. A sample of blood at 25oC has a pH of 7.34. What is the [H3O+] in this solution?
a 4.6 x 10-8 M
b. 6.5 x 10-4 M
c. 2.2 x 109 M
d. 8.7 x 10-1 M
e. 4.6 M
6. An aqueous solution at 25oC has [OH-] = 1.0 x 10-5 M. What is the pH of this solution?
a. 5.00
b. 3.00
c. 2.00
d. 9.00
e. 4.70
7. An aqueous solution at 25oC has [OH-] = 5.0 x 10-10 M. What is the pH of this solution?
a. 10.00
b. 4.70
c. 5.00
d. 9.30
c. 0.70
8. An aqueous solution at 25oC has [H+] = 5.0 x 10-10 M. What is the pH of this solution?
a. 9.30
b. 0.70
c. 5.00
d. 4.70
e. 10.00
9. The pH values of five solutions are given below. Which is the most alkaline?
a. pH = 4.5
b. pH = 13.0
c. pH = 0.0
d. pH = 1.0
e. pH = 7.0
10. Which of the following solutions is basic?
i. [H3O+] = 2 x 10-8 M
ii. [OH-] = 2 x 10-6 M
iii. [H3O+] = 9 x 10-6 M
a. i , ii, and iii
b. iii
c. ii
d. i and ii
Explanation / Answer
1) The answer of this problem is option (e), because -
A) A high pH value does not corresponds to a high H+ concentration. In acids the concentration of H+ is high but still the value of their pH is very low (below 7)
B) Stomach acid does not have a high pH value.The pH of our stomach acid varies, from 1-2 up to 4-5.
D) Pure water has a value of pH 7(Neutral point).
E) pH has very applications in our day to day life because each and every day we deals with many acids and bases and use them.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.