<p>90 grams Water * (1 mol / 18 grams) = 5 mol water.</p>
<p>But I was asking to things when I said that:</p>
<p>1.Do you use grams for chem?
2.What would be the whatever number…</p>
<ol>
<li><p>Should’ve been the 1st thing you learned. SI units.</p></li>
<li><p>What number?</p></li>
</ol>
<p>“Do you use grams for chem?”</p>
<p>What class have you been taking this entire year?</p>
<p>I’ll try to clear up the confusion. Feel free to add on.
Finding number of particles is easy, people have clarified it above.</p>
<p>Now you’ve probably learned about moles, molar mass, and mass.
I’ll give you a simple question: How many moles are in 25 grams of NaCl?
(you should write this down to avoid confusion)</p>
<p>The equation which you NEED TO MEMORIZE: moles = mass / molar mass
Mass is the normal mass that you think of. It’s usually given. In this case it’s 25 grams.
Molar mass is usually found by using your periodic table. Na=22.9 grams. “One sodium” does NOT WEIGH 22.9 grams. Molar mass is the weight of 1 mole (6.02 x 10^23) of that substance. So if you took 6.02 * 10^23 individual sodium particles you would get 22.9 grams.
Add up the molar mass of sodium (Na) and chloride (Cl). 22.9 + 35.5 = 58.4 grams
Now plug into your equation to find moles.</p>
<p>The meaning of “moles” is just a unit. No one wants to say “Pour 3.4 * 10^4363 particles into the beaker please.” That’s plain stupid. As someone else said, “It’s like saying 1 dozen eggs is equal to 12 eggs.”</p>
<p>When you get more advanced, moles and molar mass can be used to find many things like concentration and molecular formulas. If you have an unknown substance at a crime scene, you can find out what it is. (That’s a cheesy example but you know what I mean).</p>
<p>Edit:
I personally write “molar mass” as MM to avoid confusion from too many m’s.</p>
<p>1.Sorry I just had a moment we have been doing on chemical equations and stuff… <em>bushzs</em></p>
<p>2.arbitrary number</p>
<p>@aStyle THANK YOU!!! You totally explained it PERFECTLY! I finally got it! Thank you again 
</p>
<p>@Everyone else (esp MIT) Thank you as well and sorry if I called you ■■■■■■ and other things on other threads I have been made in a “believer” lmao Anyway thank you all :)</p>
<p>No prob</p>
<p>Make sure you have the right units which are the SI units. For liquids we don’t use quarts, we use liters…and to go from liters to moles requires 1 more step. I don’t know how far you are though…</p>
<p>Geez, you just convert stuff like you would convert with regular units like feet and inches…is it really that hard.</p>