# I'm having trouble converting moles to grams and finding the mass of molecules.

Problems I'm stuck on:

What is the mass in grams of .99x10^49 Sodium Chloride Molecules?

and How many moles of Cu are in 9.61 grams?

and How many moles are in 5.94x10^45 Ne atoms?

I just really need to know how to solve these. Thanks.

## <<What is the mass in grams of 0.99x10^49 Sodium Chloride Molecules?>>

First find out how many moles that is by dividing by Avogadro's number, 6.02*10^23 molecules/mole. You get 1.64*10^25 moles. Then multiply that result by 58.5 gm/mole, the molar mass of NaCl.

You will get a very large number, comparable to the mass of the Earth. Are you sure you copied the problem correctly?

<<How many moles of Cu are in 9.61 grams?>>

Divide by the atomic mass of Cu, 63.5 g/mole

<<How many moles are in 5.94x10^45 Ne atoms?>>

Multiply that by the atomic mass of Neon, which it would be a good idea to look up, so that you get some practice doing this sort of thing.

## The two pertinent pieces of information are here.

mols = grams/molar mass

There are 6.02 x 10^23 anythings in a mol; therefore,

mols = # atoms/6.02 x 10^23

or

mols = # molecules/6.02 x 10^23

Let me know if this doesn't help but explain in detail what the problem is.

## Well, you know that twelve of anything is a dozen of them.

In exactly the same way, 6.022*10^23 of atoms or molecules is a mole of them.

## To solve these problems, you will need to use the concept of molar mass and Avogadro's number. Let's break down the steps to solve each of these problems:

1. What is the mass in grams of .99x10^49 Sodium Chloride Molecules?

To find the mass of sodium chloride molecules, you need to know the molar mass of NaCl. The molar mass of NaCl is the sum of the atomic masses of sodium (Na) and chlorine (Cl). Now, using the periodic table, you can find the atomic masses of Na and Cl, which are approximately 22.99 g/mol and 35.45 g/mol, respectively. Adding these two atomic masses gives you the molar mass of NaCl, which is 58.44 g/mol.

Now, you have the molar mass of NaCl, which means that one mole of NaCl weighs 58.44 grams. To convert the number of sodium chloride molecules to grams, you can use the following equation:

Number of grams = (Number of molecules / Avogadro's number) x Molar mass

So, for your problem, the calculation will look like this:

Number of grams = (0.99 x 10^49 molecules / 6.022 x 10^23 molecules/mol) x 58.44 g/mol

Simply perform this calculation, and you will get the mass in grams of the given number of sodium chloride molecules.

2. How many moles of Cu are in 9.61 grams?

To find the number of moles of copper (Cu) in a given mass, you need to divide the mass by the molar mass of copper. The molar mass of Cu is approximately 63.55 g/mol. So, using the formula:

Number of moles = Mass / Molar mass

For your problem, the calculation will be:

Number of moles = 9.61 g / 63.55 g/mol

Perform this calculation, and you will obtain the number of moles of copper in 9.61 grams.

3. How many moles are in 5.94x10^45 Ne atoms?

Similar to the previous problem, to find the number of moles, you need to divide the given number of atoms by Avogadro's number. Avogadro's number is equal to 6.022 x 10^23 atoms/mol.

The equation to find the number of moles is:

Number of moles = Number of atoms / Avogadro's number

For your problem, it would look like this:

Number of moles = 5.94 x 10^45 atoms / 6.022 x 10^23 atoms/mol

Perform this calculation, and you will obtain the number of moles in 5.94x10^45 Ne atoms.

Remember to use the correct units and significant figures in your calculations.