nosi

3.45 g of Fe is exposed to excess chlorine gas, forming FeCl3 and releasing 24.6 kJ of heat in the following chemical reaction: 2 Fe (s) + 3 Cl2 (g) --> 2 FeCl3 (s). Find ΔHrxn.

This is more of a mathematical than a chemical question, really.

Br2 is a liquid with a density of 3.03 g/mL. Determine the pressure in atm exerted by a column containing Br2 at a height of 1000 mm. The density of mercury is 13.6 g/mL.

I actually know that the answer is 0.293 atm - and I know how to get it.

What I don't understand is why the gas law equation doesn't seem to be making sense here.

Rearranging for density, the gas law can be written as MP=dRT. If I put density and pressure on the same side, I should be able to say that since P/d=RT/M, P1/d1=P2/d2. Right?

But in this case, the way to get to the answer is 3.03*1000/13.6. This implies the relationship P1*d1=P2*d2. Why?

So I've got all my data mapped out in STAT-EDIT-L1 and L2. It's pretty simple math, really. PV=k, so 2P*.5V=k, 20P*.05V=k, and so on.

I have all the values entered, but now do I make it store it in y1=?

My math is ok, but the calculator is frustrating.

Thanks for the help, and I'll totally vote you up if you can help extricate me from this ephemeral technological quagmire.

I'm working on a statistics project that involves suicide rates, and I have data from several countries spanning 16 years. I need to calculate how much these rates are increasing or decreasing over time, and I'm not seeing a function for this.

Also, a potential problem is that there are gaps in my data for certain years in some countries, and I need excel to skip those years and not treat them as zeroes.

Any advice would be greatly appreciated.

Assume that a random sample is used to estimate a population proportion p. Find the margin of error E that corresponds to the given statistics and confidence level.

n=600, x=480, 90% confidence.

I don't see how to find E without the std. deviation. Can anyone help me out here?

My mom would always insist on taking cold water to put on the stove for tea, coffee, etc, instead of using hot water from the tap. She cited "toxic stuff from the water heater pipes," or words to that effect.

Is there validity to this - or should I start saving myself some time in the morning?

So if i^2 = -1 and i^4 = 1, that makes sense as i is the square root of -1. But what does i do as you raise it to higher powers? Could someone help me make sense of this?

And if not, why not? having a little confusion in the moment.

Someone just asked a question about this, and I answered - I think I'm right, but I'd love to hear it spelled out.

Here was the original question:

So the radical I have is

(sq root of 3 * x) (sq root of 3 * x)

I get 3x^2? Is this the correct answer?

I don't see how you could come up with 3x^2 here. But I'd be happy to be proven wrong. Here was my answer - is this correct? If not, why not? Thanks!

If I'm understanding you correctly, you have the square root of (3x), not the square root of (3 to the power of x).

So,

sqrt(3x) * sqrt(3x) = [sqrt(3x)]^2 = 3x

Or, if it was:

sqrt(3^x)^2 = 3^x

But if it was:

[sqrt(3)^x]^2 = 3^2x

Photolysis is important in photosynthesis because

Select one:

a. it accounts for the oxygen present in our atmosphere

b. it replaces electrons boosted from photosynthetic pigments

c. it sets up the hydrogen ion gradient needed to phosphorylate ADP

d. all of the above

Assume that adults have IQ scores that are normally distributed with a mean of 102 and a standard deviation of 15. Find the third quartile, Q(subscript)3, which is the IQ score that separates the top 25% from the others.

Is it [sqrt(x)]^3?

While in your digestive tract, proteins are digested. If egg whites containing the protein, albumin, are digested, name the resulting monomers.

And remind what exactly are monomers? Obviously they are (one) of something...

1/a+1/b=1/c

Solve for c.

Please show me step by step?

f(x) = 6/(x+2)

g(x) = 3/x

(f o g)(x) = ?

What is the domain of (f o g)?

Here is my equation: 16=6.39e^(97k)

I am trying to solve for k. I know natural log should probably figure in here somewhere.