Answer:
The net charge on each lysine molecule would be -1.
Explanation:
- <u>When the pH is above 2.2</u> the deprotonated form of the carboxylic acid is more present, while the amino group and side chain (which is also amino) remain protonated (with a positive charge):
R-COOH ↔ R-COO⁻
R-NH₃⁺
R'-NH₃⁺
Net charge = +1
- <u>When pH is above 9.0</u>, the carboxyl group remains deprotonated, while the amino group is deprotonated and the side chain is protonated:
R-COOH ↔ R-COO⁻
R-NH₂
R'-NH₃⁺
Net charge = 0
- <u>When pH is above 10.5</u>, the carboxyl group remains deprotonated, while both the amino group and the side chain are deprotonated:
R-COOH ↔ R-COO⁻
R-NH₂
R'-NH₂
Net charge = -1
So at pH=13 (which is above 10.5) the net charge is -1.
Remark
The question with these kind of problems is "Which R do you use?" That's where dimensional analysis is so handy. You must look at the units of the givens and choose your R accordingly. You'll see how that works in a moment.
You need to list the givens along with their units and in this case the property you want to solve for. You need all that to determine the R value
Givens
n = 0.25 moles
T = 35°C = 35 + 273.15 = 308.15°K
V = 6.23 L
Pressure = P in kPa
Which R
The units of the R you want has to have units of moles, kPa, °K and liters
The R that you want is 8.314
<em><u>Formula</u></em>
PV = nRT
P 6.23 = 0.25 * 8.314 * 308.15 Combine the left
P*6.23 = 640.5
P = 640.5/6.23 = 102.81 The answer should be 100 kpA of 1.0 * 10^2 kPa
because the number of moles has only 2 sig digs.
But if sig digs are not a problem 102.8 is likely close enough.
Second Question
You are going to have to clean up the numbers. I think I've got only 1 chance at this. The partial pressures of the 2 gases will add up to the total pressure. So the total pressure was 100 approx and the water vapor was 3.36 kPa. The difference is
Total = air + water vapor
100.18 = air + 3.36 about Subtract 3.36 from both sides.
100.18 - 3.36 = 96.82 about. Pick the answer that is closest to that. I'll clean up the numbers if I can.
Answer C
Answer:
-191.7°C
Explanation:
P . V = n . R . T
That's the Ideal Gases Law. It can be useful to solve the question.
We replace data:
2.5 atm . 8 L = 3 mol . 0.082 L.atm/mol.K . T°
(2.5 atm . 8 L) / (3 mol . 0.082 L.atm/mol.K) = T°
T° = 81.3 K
We convert T° from K to C°
81.3K - 273 = -191.7°C
The correct answer would be: D. Natural gas
This would be the correct answer since natural gases are considered a fossil fuel. The other options are renewable resources. Corn can be reproduced. Wind is a source of energy which makes it renewable. Geothermal is also a renewable resource since its heat is from the earth's core which could be used multiple times.
Hope this helps! :3
