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Can someone help me with some Chemistry problems?

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Okay. On the back of our homework we have an answer key with the correct answers to each equation. I have done these problems multiple times and keep coming up with the same wrong answer. I was hoping someone could work them out so I could see where I went wrong. Thank you.

1.) The density of water is 1.00 g/cm^3 at 4 degrees C. What is the density in tons/yds^3? (1 ton = 2000 lb, exact)

-It seems simple but every time I do it I get the answer as .0512 tons/yds^3, which is wrong.

2.)If gold is selling for 675 dollars an ounce, what is the value of 1.00 in^3 of pure gold, given that the density of gold is 19.3 g/cm^3?

-This one, I don't even have any idea how to start...please help!

aaand

3.) A small creature moves at the rate of 3.00 furlongs per fortnight. If a furlong is exactly 220 yds, and a fortnight is exactly 2 weeks, then how fast is the creature moving in cm/hour?

- I always get 180 cm/hr , which is again...wrong. Can anyone help?

I also have this other one, but I don't want to ask too much of anyone so if you just want to help me with one more for fun ( :D) Then I also have this one.

9.) An atom of gold weighs 3.272 X 10^-22 grams. how many gold atoms are in a 5.00 lb of gold.

- I keep getting 7.43 X 10^-19......which is..of course wrong...

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  1. Your problem is that you are multiplying when you should be dividing, and vice versa.  If you need an answer in tons per cubic yard, you calculate a figure in tons and divide by cubic yards; it's as simple as that.

    For instance, a foot is 30.48 centimeters so a yard is 91.44 centimeters.  A cubic yard thus contains (91.44)³ cubic centimeters, or the same number of grams of water at 4°C.  To convert this number to tons, multiply by 0.002205 to convert it from grams to pounds, then divide by 2000 to get (short) tons.  I get 0.843 tons/yd³.

    Question 2 assumes that you know an inch is 2.54 cm.  Thus a cubic inch is 2.54³ cc, a cubic inch of gold is 19.3*2.54³ grams, and you can divide by the number of grams per ounce to get ounces.  (Careful; does the question assume standard ounces or Troy ounces?)

    Question 3... same sort of thing.  3 furlongs is 660 yards, which you convert to centimeters by multiplying by 91.44 cm/yd (notice that dividing yards by yards yields 1, so your answer is in centimeters).  A fortnight is 336 hours, so dividing by 336 hours yields an answer in cm/hour.

    Question 9 looks like you multiplied by 3.272*10-²² when you should have divided by it.  Remember, if you divide a quantity in grams by another quantity in grams/atom, the answer has the units of atoms (grams/grams = 1, 1/(1/atoms) = atoms).

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