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AnthonyJ
May 21, 2010, 08:09 AM
Hi, can someone help me with this question please!
The Atlantic Ocean contains about 9.0 lb (1 lb = 454g) of Gold per cubic square mile. How many moles of Gold are there per cubic mile?

Any help would be greatly appreciated.

Curlyben
May 21, 2010, 08:14 AM
How is a mole defined ?
How much does a mole of Gold "weigh"
This will give you what you need to answer this question.

Unknown008
May 21, 2010, 09:11 AM
You should know that one mole of an element has the mass equal to it's relative mass in grams.

Hydrogen gas has a relative molecular mass of 2. So, one mole of hydrogen gas will have a mass of 2 g.

Similarly, oxygen gas has an Mr (relative molecular mass) of 32, hence, one mole of oxygen gas has a mass of 32 g.

Does it help?

Post your answer. :)

EDIT: To clear up things, if you are dealing with a metal, then the mass of one mole of that metal is directly it's relative atomic mass in grams. Sodium has an Ar (relative atomic mass) of 23, so, 1 mole of Na will weigh 23 g.