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:
B They move because of the convection currents in the mantle.
LiOH is soluble. Na2CO3 is soluble. Cu(OH)2 is insoluble.
First step is to balance the amount of atoms on each side
So for example if my equation that I have to balance is : Br2 -> Br-
First thing I would have to do would be :
Br2 -> 2Br-
Then I would have to balance the charges on both sides. So because there is a -2 charge on the right side I will have to add a -2 charge onto the right side as well. I would do this by :
Br2 + 2e- -> 2Br-
And now you can see the amount of atoms and the charges are balanced... So your overall reaction is now balanced too.
The answer that best completes the statement above is EXTENSIVE LAVA FLOW. Maria is the name that refers to an asteroid family. And this has punctured the surface of the moon which created magma to bleed out and resulted in an extensive lava flow. Hope this answer helps.
