Need help understanding a mole and Avogadro's number question for Chemistry?

Question

If I get help for one of these, I'll understand the rest. I just get a little confused. Okay, here is the question:

How many molecules are in 3.4 moles of water?

I know how to set it up, I'm just not sure how to calculate it. Please, help! My grade depends on you!

Answer 1

1 mole = 6.022 x 10^23 atoms or molecules

3.4 moles x (6.022 x 10^23) = 20474800000000000000000000 molecules or
2.04748 x 10^25 molecules of water

Answer 2

Everyone so far is basically correct, but I think they might not have explained the part you are struggling with. And that is "why 'mole' in the first place?" The word has the same source as 'molecule'.

You know how elements have atomic weights? A mole is the number of atoms it would take to make up an atomic weight's worth of grams. The same with molecular weight and compounds. This is also known as the Gram Molecular Weight.

The molecular weight of water is 32. One mole of water molecules weighs 32 grams. The number of molecules (or atoms, for an element) in a mole, weighing its gram molecular weight, is 6.022*10^23 - or Avogadro's number.

So with your question, 3.4 moles of water contain 3.4*6.022*10^23 (or 2.047*10^24) molecules. And weighs 108.8 grams.

Answer 3

Avogadro's Number (Z) = 6.022 x 10^23
This number is the value of the number of atoms/molecules in one mole of an element/molecule.
So if you have 3.4 moles of water you just multiply the two numbers together.
3.4 x 6.022 x10^23 = 2.047 x 10^24

NB Multiply the two coefficients together (3.4 x 6.022 = 20.4748)
This value is then adjusted for scientific/standard notation.
20.4748 = 2.04748 x 10^1
Now adjust the powers of 10.
2.04748 x 10^1 x 10^23 = 2.04748 x 10^24
Adjust the Significant numbers to four as per Avogadro's Number.
2.04748 X 10^24 = 2.047 x 10^24 (4 sig. fig).

Answer 4

Hiyah! ok, first enable's see what a mole potential, suited? this is defined because of the fact the quantity of any substance that incorporates as many undemanding entities (e.g., atoms, molecules, ions, electrons) as there are atoms in 12 grams of organic carbon-12 (12C), the isotope of carbon with atomic weight 12. yet,what does this propose? think of a ball, ok? I call it carbon and weigh it to be as 12 grams. Now,i'm getting a heavier ball and that i weigh it. It seems to be two times the load of Carbon. which potential it would be (12 grams*2) 24 grams, suited? I call it Magnesium. ok, ok so we've got a coarse theory of what the moleis. yet what's the Avogadro consistent? easily, Avogadro suggested that onemoleof a substance e.g. a million mole of Magnesium Or a million mole of carbon will constantly have 6.023*10^23 debris. Now debris can propose atoms or molecules. So now all of us comprehend each mole of a substance has 6.023*10^23 debris. ok i'm going to offer you an person-friendly thank you to sparkling up those variety of questions. Mass of substance= mass of a million mole of substance * No. of moles So calculate mass of Ag3PO4 using the periodic table, using the atomic mass, i'm going to make it easier to in the 1st question: (using periodic table) Ag3PO4= (107.87) *3* (31)*(sixteen)*4 Use that equation for the 1st 2 questions. Now the subsequent 3 questions. Hmm, Now all of us comprehend that 1mole= 6.02*10^23 atoms So locate out first rearranging the above equation the no. of moles. Mass of substance /mass of a million mole= No. of moles (for first question) 3.5g / (using periodic table) sixty 4= 0.05 moles So, if a million mole= 6.02*10^23 debris 0.05moles * 6.02*10^23particles= No. of atoms in 3.5g of copper i desire you are able to sparkling up something of the questions with the aid of this methodology. stable success x

Answer 5

Okay.

So "Avagadro's Number" is just a very big number that makes dealing with things as tiny as atoms & molecules much easier....a "mole" is just 6.02214179 x 10^23 of something. So one mole of water (H2O) will contain two moles of hydrogen & one mole of oxygen, or (2 * 1.01 g
+ 16.00 g = 18.02 g of water)...

So 3.4 moles of water contains 3.4 x Avagadro's Number of molecules, or 3.4 x 6.02 x 10^23 molecules, very roughly 20,474,800,000,000,000,000,000,000,000 molecules!

Answer 6

ok, avogadro's number is 6.02e23 atoms or molecules per mole
3.4 moles H2O x (6.02e23 molecules/ 1 mol) = 2.05e24 molecules H2O

Answer 7

3.4 x (6.02 x 10-23rd power).