Which of the following statements about the pH of 0.010 M HClO4 is correct? pH=2.00, because [H+]=1.0×10−2M.

A: p H equals 2.00 , because the molar concentration of H with a positive 1 charge equals 1.0 times 10 to the negative 2 power molar .

pH=2.00, because [H+]=2.0×10−2M.

B: p H equals 2.00 , because the molar concentration of H with a positive 1 charge equals 1.0 times 10 to the negative 2 power molar .

pH>2.00, because HClO4 is a strong acid.

C: p H is greater than 2.00 , because H C l O 4 is a strong acid.

pH<2.00, because HClO4 is a weak acid.

Option B: p H equals 2.00 , because the molar concentration of H with a positive 1 charge equals 1.0 times 10 to the negative 2 power molar .

pH = 2 because [H⁺] = 1×10¯² M

Explanation:

To know which option is correct, we shall determine the pH of the 0.010 M HClO₄ solution. This can be obtained as follow:

We'll begin by calculating the concentration of the hydrogen ion [H⁺] in the solution. This is illustrated below:

HClO₄ is a strong acid and will dessociates as follow:

HClO₄ (aq) —> H⁺ (aq) + ClO₄¯ (aq)

From the balanced equation above,

1 mole of HClO₄ produced 1 mole H⁺.

Therefore, 0.010 M HClO₄ will also produce 0.010 M H⁺.

Finally we shall determine the pH of the solution. This can be obtained as follow:

Concentration of the hydrogen ion [H⁺] = 0.010 = 1×10¯² M

pH =?

pH = –Log [H⁺]

pH = –Log 1×10¯²

pH = 2

Thus,

The pH = 2

because,

[H⁺] = 1×10¯² M

Thus, option B gives the correct answer to the question.

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.

the answer is 303.15 or 303