[DeadSerious]

       I don't know what is going on with my chemistry book or the youtube videos.Every single time I calculate the answer, whether it's on paper or on a online chemistry calculator, I never come up with the "supposedly" correct answer.I find this very discouraging;  because to me, a simple formula should not be this hard to do. For example, my chemistry study guide says "Convert 63 grams of ammonia to molecules".Part of the solution was to multiply 63 by 1 moles NH3 and divide by 17.03.The result in the book says 3.7 moles.My result is roughly 2.7 no matter how many times I do on paper or on a calculator.Another example is from youtube.On one of the videos, there was an example question to do.It said "What is the weight (in grams) of 4.8 X 10 to the 24th power atoms of C? One possible solution shown was to divide 4.8 x 10 to the 24th power atoms C by 6.02 x 10 to the 23rd power. The result is 8. My results varied immensely.On one chemistry calculator I got infinity; On the rest of the calculators I got around 37.So this leads me to two questions.One, is the book and youtube video correct or me and why? Two, can any of you recommend an accurate chemistry calculator that I should use? Any help would be very much appreciated!

[mikasaur]

With these types of questions it's extremely helpful to write out what you're doing and to include units. Including units is one of the best ways of making sure your answer makes sense.

       Convert 63 grams of ammonia to molecules

For something like this, I would set it up as:

[itex]63 \textrm{ g }\ce{NH3}\times \frac{1 \textrm{ mol }\ce{NH3}}{17.03 \textrm{ g }\ce{NH3}}\times \frac{6.022\times10^{23} \textrm{ molecules }\ce{NH3} }{\textrm{mol }\ce{NH3}}[/itex]

Note how nicely the units cancel. After multiplying the 63 by the [itex]\frac{1}{17.03}[/itex] you'll see that there are 3.7 moles like your book says. Multiply by Avagadro's Number and you get your final answer in molecules NH₃.

[sjb]

       I don't know what is going on with my chemistry book or the youtube videos.Every single time I calculate the answer, whether it's on paper or on a online chemistry calculator, I never come up with the "supposedly" correct answer.I find this very discouraging;  because to me, a simple formula should not be this hard to do. For example, my chemistry study guide says "Convert 63 grams of ammonia to molecules".Part of the solution was to multiply 63 by 1 moles NH₃ and divide by 17.03.The result in the book says 3.7 moles.My result is roughly 2.7 no matter how many times I do on paper or on a calculator.

Consider your 17-times table. Is 2.7 reasonable?

Another example is from youtube.On one of the videos, there was an example question to do.It said "What is the weight (in grams) of 4.8 X 10 to the 24th power atoms of C? One possible solution shown was to divide 4.8 x 10 to the 24th power atoms C by 6.02 x 10 to the 23rd power. The result is 8. My results varied immensely.On one chemistry calculator I got infinity; On the rest of the calculators I got around 37.So this leads me to two questions.One, is the book and youtube video correct or me and why? Two, can any of you recommend an accurate chemistry calculator that I should use? Any help would be very much appreciated!

I think you may also need to manually cancel powers of ten at some stage. I'm not really sure where either 37 comes from here. Do you have an link to this calculator? Sometimes it may be a radian/degree issue but this shouldn't be relevant here.

[Borek]

Please write what is the calculator that you use, and how you key in the numbers. 63/17 is 3.7:

http://www.wolframalpha.com/input/?i=63%2F17&dataset=

4.8×10²⁴/6.02×10²³ is 8 (more precisely 7.97..., which is pretty close to :

http://www.wolframalpha.com/input/?i=4.8*10^24/6.02*10^23&dataset=

or

http://www.wolframalpha.com/input/?i=4.8e24/6.02e23&dataset=

Doesn't matter what calculator you use - as long as you enter the data correctly, these are the results you should get. It has nothing to do with chemistry, this is simple arithmetic.

[DeadSerious]

  I never thought about dividing 63 by 17 because I thought I was suppose to multiply 63 by the
 Avogadro's number and then divide by 17. Was I not suppose to do that? 

Anyway, this is the link that gave me infinity as an answer:http://www.creative-chemistry.org.uk/alevel/calculator.htm

   This is one of the links that gave me a number close to 37: http://www.mathgoodies.com/calculators/calc4chem.html

    This is another one of the links that gave me a number close to 37:  https://scilearn.sydney.edu.au/fychemistry/calculators/chemical_calculator.shtml

[Borek]

  I never thought about dividing 63 by 17 because I thought I was suppose to multiply 63 by the
 Avogadro's number and then divide by 17. Was I not suppose to do that?

[tex]\frac {63} {17} N_A = \frac {63N_A} {17}[/tex]

In this case order of operations doesn't matter. You can calculate number of moles (63/17) and then multiply it by N_A, you can multiply 63 by N_A and the divide by 17, these are perfectly equivalent. I really, really suggest you brush on the basic math, as it seems that's where your problem is.

This is one of the links that gave me a number close to 37: http://www.mathgoodies.com/calculators/calc4chem.html

Which just means you entered the numbers incorrectly, as it gives 7.97 as expected.

[DeadSerious]

 Mikasaur, thank you a immensely! You literally cleared everything for me. Seriously, I thought 1 mol NH3 was a short way of  saying the Avogadro's number.So I thought I was supposed to multiply that number(Avogadro's number) by 63 and THEN divide by 17.03.I'm very new to this kind depth Chemistry and I'm glad you weren't quick to judge me of this dumb mistake.Thank you very much again!

[DeadSerious]

Borek, I don't have problems with basic math at all; I'm new to learning this kind level chemistry. I got the answers wrong because I misread 1 mol NH3 to be the abbreviation for the Avogadro's number.Therefore, I multiplied 6.022x10 to the 23rd power by 63(before dividing by 17.03) when I shouldn't have.

[mikasaur]

Glad I could help, DeadSerious!

Though I should admit that reading how I helped you kind of confuses me.

Therefore, I multiplied 6.022x10 to the 23rd power by 63(before dividing by 17.03) when I shouldn't have.

That should work. As Borek stated, the order of operations don't really matter.

You could multiply N_A (Avagadro's number) by 63 and then divide by 17.03 or you could divide N_A by 17.03 and then multiply the quotient by 63.

Regardless, I hope setting up your calculations with units helps you to see exactly what is going on. I find that it helps to make sure I'm multiplying where I'm supposed to be multiplying and dividing where I'm supposed to be dividing. And if I find that my units don't make sense then I've gone wrong somewhere.

I might find a friend/tutor/teacher who can review your approach to these questions. It sounds like you finally got it, but it also sounds like you had some trouble operating the various calculators you had. It's hard for us to see where you might be going wrong without literally watching you do it over your shoulder.

[Borek]

I got the answers wrong because I misread 1 mol NH3 to be the abbreviation for the Avogadro's number.

You didn't misread anything. 1 mol NH₃ means N_A molecules of NH₃.

Therefore, I multiplied 6.022x10 to the 23rd power by 63(before dividing by 17.03) when I shouldn't have.

And - as you were already told several times - this approach should produce a correct answer, not an infinity nor 37.