Monday, November 16, 2009

What does one mole equal? how do you find how many moles are in something?

is one mole avagadro's number?

i chose 3 questions to answer and i only need to asnwer one but im not sure how to do any-which one should i do

1.a mole of moles [the animal] placed from nose to tail would reacch from here to Pluto and back how many times?

2. how many atoms of carbon are there in the hope diamond?

3.a mole of water weighs about 18 grams. how many moles of water are there in the Atlantic Ocean?

can someone pleeeeaaseee help me understand how to answer them??

What does one mole equal? how do you find how many moles are in something?
1. find the length of a mole(animal) eg..2meters and multiply by 6.02*10^23. then divide that distance by the distance from here to pluto

2. find the mass of the hope diamond.divide by 12grams.multiply answer by 6*10^23

3.find out how many litres of water in the ocean,1litre water=1kilogram,divide answer in kilograms by .018 and that will give your approximate answer(it is approximate due to the assumtion that the atlantic ocean is fresh water..


somebody above has said a mole is not a universal constant??

The mole is one of the few universal constants. it is even regarded as a basic S.I unit of which there are only 7

eg metres,seconds,kilograms,candela,Amperes... and the mole

yet another example of people talking s***
Reply:Nothing to do with Avogadro. A mole is a quantity (in grams) that equals the molecular number of the substance. Oxygen has atomic number 16, hydrogen 1, so H2O = 2*1+16=18. So indeed a mole of water is 18grams. The mole (animal) is something like a rat. The qustions (1, 2, 3) you have are rather like quizes, they don't really have answers. They are there in order to show you the different meanings of the word mole.
Reply:the mole is not a universal constant

for me the less tricky is the 3rd question

1 mole = mass(g)/M(molecular weight that can be calculated with use of periodic table)

That is why 1 mole of H2O weights 18 grams (1 mole=x grams/(2+16); x=18 g.

now you just have to find what is the weight of the water in the Atlantic Ocean ;)
Reply:1 mole = 6.02 x 10^23 atoms or molecules of a substance


1 mole = the molecular weight (or atomic weight) of a substance ion grams


1 mole = 22.4 liters of any gas at STP.

question 2 is probally the easiest to solve..Find the weight of the Hope Diamond in grams and then divide by 12 (the atomic weight of carbon) to find the number of moles.
Reply:One mole of anything is Avogadro's number of those things - 6.02 * 10^23. So, for the first question you would need to find the distance to Pluto and the average length of a mole (the animal). For the second question you would need the weight of the Hope diamond, then look on the periodic table to find the atomic weight of carbon (diamonds are pure carbon). For the third question you would need to find out how much water is in the Atlantic ocean.
Reply:It is very simple

You are probably familiar with a dozen. In a dozen there could be 12 cows, 12 oranges or 12 anything.

A mol is similar to the dozen concept. If you have a mol of something, it means you have 6.02x10^23 of anything. This quantity 6.02etc is know as the avogadro number.

So lets look at your third question:

1 mole water is 18 grams.

Find the total volume of water in the ocean and multiply by the density, say x

So if 1 mole is 18 g

then N mole will be x g

x = 18 * N / 1
Reply:A mole, also known as avogadro's number, is 6.022x10^23. That's a bigger number than most of us can really comprehend, so think of it like a really big dozen.

For answer 1, you need to know how long the average mole (animal) is, and how far it is to Pluto. Say they're 6". So just multiply that out and you'll have your distance.

For 2, you need the weight of the hope diamond. The weight of a mole of carbon atoms is 12 grams--carbon is the standard on which the mole is based.

I wouldn't answer #3, because it's based on a false assumption that the ocean weighs what standard water does--there's the matter of salt in there, and if you wanted extra credit you could factor in salinity and the weight of the salt.

A lot of chemistry is making sure your units cancel and equations are balanced. You shouldn't have much of a problem if you're careful.
Reply:First you got to find out how much the Hope Diamond weighs in grams 45.52 carats equals 9.104 grams (that is the weight of the diamond by itself.

Now we can convert 9.104 grams to moles

12.011 grams equals 1 mole

9.104/12.011 = .758 Moles of carbon

A mole equals 6.0221415 × 10^23 atoms

multiply that by .758

that will give you how many carbon atoms are in the hope diamond
Reply:Q1...1 mole of moles requires Avagadro's number (6.02 x 10^23). If you had this many moles, you need to multiply it by the length of a mole and this will give you the length of 1 mole of moles. If you know how many inches to pluto, divide the length of the mole of moles by the distance to pluto (make sure the units are the same) and it will tell you how many times it will reach to pluto and back. need to know the mass of the hope diamond in grams. Then you divide the mass of the diamond by the atomic mass of carbon (12.001g/mol) and you will be left with the moles of carbon in the hope diamond. This is all assuming the diamond is 100% carbon. If not, take the percentage of carbon times the mass of the hope diamond and run that result through the above calculation.

Q3...You will need to know the percent water in the entire Atlantic. Multiply that by the mass of all the water in the Atlantic (in grams) and then divide that by 18 g/mol (molecular mass of water) and you are left with moles of water in the Atlantic.

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