1.Your cell-preparation protocol calls for you to prepare EXACTLY 1000 mL of dilute room temperature phosphate buffer solution. You use boiling water to quickly dissolve your phosphate salt. You carefully measure out exactly 1000 mL of this solution when it is still at 55C. Once the buffer solution has cooled to room temperature (20C), how much more or less volume solution do you actually have? Use a volume expansion coefficient for water at 55C of 4E-4.

(Be careful with your signs! Remember that a postive difference will be an increase in volume and a negative difference will be a decrease.)

V = ___________mL

Note: This is why most analytical chemistry measurements are done by weight, not by volume!

2.Consider the same rider as in the previous problem, but now all bundled up (trying to sweat out some water weight, I suppose), and thus not evaporating much water to the surroundings. Being unable to regulate their body temperature now, by how much does their body temperature rise in 55 minutes of this exercise? (The average heat capacity of the human body is ~3500 J/(kg-K))

[From the previous problem: A 75 kg cyclist rides their bike at 15 km/h. The air temperature outside is the same as that of the skin, approximately 34C. The power consumption during this exercise is 300 W and the body's net efficiency in converting metabolic energy into cycling energy is approximately 25 percent.]

T = ______________C

3.If the thickness and area of a uniform windowpane are doubled, the rate at which heat is conducted through the windowpane is A. halved. B. increased by a factor of four. C. unchanged. D. decreased by a factor of four. E. doubled.

4.If you were to lie outdoors all day, exposed to the sun on a hot summer day, your body temperature would rise until A. the heat absorbed by the body equaled its thermal capacity. B. the heat absorbed by the body exceeded its thermal capacity. C. it equaled the temperature of your surroundings. D. your body was losing and gaining heat at the same rate. E. your body was hot enough to reflect all the energy striking it.

5.A hot cup of tea, initially at 85 C is left to cool slowly on your desk (in a 22 C room) until it reaches drinking temperature of 55 C. The decreasing temperature of the tea is observed to follow Newton''s Law of Cooling. After 14 minutes you test the tea and find it to have reached 70 C.

How much longer must you wait before you can drink your tea?

Must wait another _________minutes

Please help me with these 5 questions and thank you spo much for your time and help:)!!!!!!