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drbob222
Answers (149)
The FitnessGram Pacer Test is a multistage aerobic capacity test that progressively gets more difficult as it continues. The 20 meter pacer test will begin in 30 seconds. Line up at the start. The running speed starts slowly, but gets faster each minute
you so fake my dude
True, A is not true. But isn't D not true also. I think, without looking it up, that ethanol has a lower boiling point than water. I remember something like 80 degrees C or so. And the question says statementS so it can have more than one answer. Check it
Sam. The message I sent was meant for the person writing the inappropriate material. It was not meant for you. We never try to ban a student who is using the site appropriately. So not to worry.
start with 47/r+9/r-5=5hrs OK to here. I will rewrite to see it more clearly. [47/r] + [9/(r-5)] = 5 multiply both sides by r(r-5) to get 47(r-5) + 9r = 5(r)(r-5) 47r - 235 + 9r = 5r^2 - 25r 47r - 235 + 9r -5r^2 + 25r = 0 -5r^2 + 81r -235 = 0 I changed the
Try X^2 -2X +1. Factored this gives (X-1)(X-1) = 0 and X = 1 and 1.
Neither. q = mass x specific heat x delta T. 5016 = 5.00 x 10^2 x Cp x 10 5016 = 5.00 x 10^3 Cp Cp = 5016/5.00x10^3 = 1.003 J/g*C (You didn't put units on your answer, a No, No.) I can understand how you might get a power of 10 off but I don't understand
I looked up Al and found the specific heat to be 0.900 J/g*C. So 50.0 x 0.900 x 100 = 4500 J.
It leaves a layer of non-moving air in the spaces and that provides some insulation.
q = mass x specific heat x (Tf - Ti). q = 50.0 g x specific heat Al x (125-25). You will need to look up the specific heat of Al metal. The units should be in Joules/gram. If the units are in J/mol, then you must change the 50.0 g Al to mols Al by dividing
To do this is simply if you remember how to convert from one denominator to the other. I start by writing the two numbers side by side like so. 5/8 = ?/40 Then 8 goes into 40 how many times? That would be 5. Then 5 x the numerator = 25, so the answer is
correct. Good work.
Yes you did it correctly and the answer is correct; however, you didn't account for the boards not putting in the spaces where they belong. These boards count one space as one space; however, two spaces, three spaces, 4 spaces, etc etc just get one space.
Answered below with an explanation.
Yes, 7.96 g is correct and the correct number of s.f. BECAUSE, 16.81 - 8.854 = 7.956 g. The least sig number is 16.81 (two places to the right of the decimal) and when we subtract, we may have in the answer no more than two places to the right of the
I posted this answer but didn't identify myself properly.
You number is correct; if you obtained it correctly from your work I can't tell. mass percent = (mass solute/100 g solution)*100 [(18.6)/(18.6 + 81.4)]*100 = (18.6/100)*100 = 18.6%
answered above.
mole fraction, yes
one degree Kelvin.
Half life is the time it takes for 1/2 the material to decay into something different. If you start with 100 marbles, (and they had a half life of 2 days), you would have 50 marbles at the end of 2 days, 1/2 of that or 25 at the end of 4 days, 12.5 at the
I didn't say it but the neutrons are neutral so they don't have the kinds of "electrical" problems that positively charged and negatively charged particles have.
Think about it. Alpha particles have a positive change which makes it difficult for them to get close to a positively charged nucleus. Right? And the beta particles (electrons which are negatively charged) must navigate through a sea of electrons of the
Generally, if bombarding with neutrons, then the nucleus becomes one neutron richer, which often results in a beta particle being released.
Close but I don't know what you used for the heat of fusion. I have 334 J/g for ice and 0.3 kg = 300 g; therefore, 334 x 300 = 100,200 J. If I use 80 calories/g, then 80 x 300 = 24,000 calories and convert that to J (x 4.184) = 100,416. So your answer is
answered below (unless you didn't like that answer).
Do you assume the volumes are additive? They are not necessarily additive but if you assume they are, then, 1 mol hexane has mass of 86.18 g and volume = mass/density = 86.18/0.660 = ??. That x 5 (for 5 mols) = volume of 5 mols hexane. Same kind of
I also get 9.24 x 10^-5 but I don't think that is the correct number of s.f. You subtracted 5.57 - 4.9320 = 0.638 but that must be rounded to 0.64 because in addition or subtraction we can't have more places after the decimal than the least precise. Then
Hydrogen K (especially high in radioactive K if we drink a lot of milk) Radium uranium Radon Polonium to list just a few of them.
k = 0.693/t1/2. Then ln(No/N) = kt No = 26.3 N = 3.29 k from above. solve for t. Post your work if you get stuck.
You're welcome. I can't believe it either. I didn't learn the quadratic in the 8th grade for sure.
(4.4 x 10^12/110)*100 = 4 x 10^12 or 4 trillion
is this how you do it-- (A+3)A=3190 Then it becomes A(squared)+3A=3190 You are OK to here. Then A^2 + 3A -3190 = 0 and solve the quadratic OR factor it. I solved using the quadratic formula because I have that formula put into my calculator. But it can be
That gives me 55 for A and 58 for U.
There are two equations. U = age of uncle A = age of aunt ============= U x A = 3190 A + 3 = U =============== Can you solve those two equations simultaneously? Or have you had that yet?
I think you MUST have meant molality. molality = mols/kg solvent 0.0368 m = mols/0.00831 kg. Solve for mols = 0.0368 x 0.00831 mols = g/molar mass You know mols and g, solve for molar mass.
delta Psolvent(lowering) = XsolutePosolvent
delta T = Kf*molality Plug in 0.085 for delta T, I assume you know Kf for water, calculate molality. Then molality x kg solvent x molar mass = grams. You have all but molar mass which can be calculated.
The molarity of the solution can't be 0.0368 m. It can be 0.0368 molar or it can be 0.0368 molal. Which is it.
convert g S to mols. (mols S/kg solvent) = molality delta T = Kf*molality delta T = Kb*molality I presume you have the constants for boiling point and freezing point for acetic acid.
Do you have the normal vapor pressure of benzene at that temperature? Or have you been told to look it up?
answered below.
m = mols/kg solvent 1 kg solvent has a mass of 1,000 g and a volume of v = m/d = 1000/1.049 = 953.3 mL or 0.9533 liters. Then Molarity = mols/L. You have 0.688 mols and you have 0.9533 L so the molarity = ?? check my thinking.
Write the equation. Use PV = nRT and solve for n, the number of mols O2. Convert mols O2 to grams O2, then %O2 = (g O2/g solution)*100 = ?? check my thinking.
mol fraction = (mols NH3)/(mol NH3 + mol H2O) = 1.00/3.44 = ?? molal = mols/kg soln. molal = 1/(2.44 x 18 g/mol x 1 kg/1000 g) = check my thinking. Check my work.
I would choose that one also.
The water molecules are dipoles. The oxygen end is negative and the hydrogen end is positive. Therefore, around the oxygen atom of one molecule will be one or more hydrogen atoms from nother molecule(s).
Use the Henderson-Hasslebalch equation.
Citric acid is the salt of a weak acid and a strong base. I would add citric acid, a weak acid. Buffers are weak acids and their salts or weak bases and their salts.
partial pressure and mole fraction
