A solution of sulfuric acid (H2SO4, 25.00 mL) was titrated to completion with 34.55 mL of 0.1020 M sodium hydroxide. What was the concentration of the sulfuric acid

0.0705 M

Explanation:

We'll begin by writing the balanced equation for the reaction. This is given below:

H₂SO₄ + 2NaOH —> Na₂SO₄ + 2H₂O

From the balanced equation above,

The mole ratio of the acid, H₂SO₄ (nA) = 1

The mole ratio of the base, NaOH (nB) = 2

Next, data obtained from the question. This include the following:

Volume of acid, H₂SO₄ (Va) = 25 mL

Volume of base, NaOH (Vb) = 34.55 mL

Molarity of base, NaOH (Mb) = 0.1020 M

Molarity of acid, H₂SO₄ (Ma) =?

The molarity of the acid, H₂SO₄ can be obtained as follow:

MaVa / MbVb = nA/nB

Ma × 25 / 0.1020 × 34.55 = 1/2

Ma × 25 / 3.5241 = 1/2

Cross multiply

Ma × 25 × 2 = 3.5241

Ma × 50 = 3.5241

Divide both side by 50

Ma = 3.5241 / 50

Ma = 0.0705 M

Therefore, the concentration of the acid, H₂SO₄ is 0.0705 M

the answer is learned

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.