How many moles of water are in one cubic meter? How do I find that answer?

Question

My Physics teacher just threw this question at us in our homework and I have no clue how to go about finding it. And my homework is due tomorrow!

Answer 1

It takes several steps.  Go from: volume of water --> mass of water --> moles of water.

The first step requires the density of water.

The second step requires the fact that there are X grams / mole of a substance where X is the atomic weight of that substance.  You'll have to look up the a.w. of H and O in a periodic table.

Put it all together and you've got it.

Answer 2

5.5 repeated

a mole is 6.023x10_23 (10 to the 23 power - or move the decimal 23 places to the right) particles of a given substance. This will be different in size and weight for every substance because a particle of water is different from a particle of salt, for example. For our purposes, however, we weren't given any particles so we'll find out another way how much a mol of h2o weighs.

ok, so we know that the atomic weight of hydrogen is 1g, and oxygen is about 16 grams, so one molecule of H2O would be 18 grams, or 18g/mol (mole)

so to find out how many moles are in that m3 (cubic meter), or how many times 18g will go into it, we need to convert the meters into grams.

1 cubic centimeter is = 1g in conversion, idk if you were told this or not but i'm telling you now and it's useful information that you'll come across anyway (3rd link has this)

now you have the info you need but you need an equation to justify this. if you're new to chemistry then this will be annoying to learn but necessary, even though i forget what it's called, but it's a way of making chemistry equations.

*please ignore the periods - i needed some way to get this window to not collapse all the spaces together when i posted it*

1m3 . . 100cm3 . . . 1g . . . . . .1mol H2O . . . . _

------- X ------------ X ------------- X ----------------- = 5.5   mol H2O  

. . . . . . 1m3 . . . . . 1cm3 . . . .18g H2O

basically the goal is to keep crossing out the diagonal likes in order to form a long sequence of conversions, then multiply all the top numbers (1 x 100 x 1 x 1 = 100) and divide by the bottom numbers ( /1 = 100, /1 = 100, /18 = 5.55555 etc.) Only the units need to match to be crossed off, and this way of forming equations shows your work and precision in your answer.

What this says is there is 1 cubic meter of H2O ( i didn't add h2o until i got to moles at the end but you should i just imply it) in 1 cubic meter of h2o - obviously so you dont need 1m3 h2o below it. Then, there is 100 cm3 in 1 m3 (you should know simple conversions, moving the decimal). Then, there is 1g of h2o in 1cm3 of h2o. Then, there is 1 mol of h2o in 18 g of h2o, so the answer is 5.5555 etc. if you go through and cross off top left to bottom right the only measurement left is mol and that's what your answer needs to be in.

use the link below, i just googled and looked around and it looks very friendly to chemistry introduction involving moles

the second was just a check-up on atomic weight because i didn't have a periodic table of elements handy. these were all through google