## Rounding

Margaret Akey
Posts: 80
Joined: Fri Sep 28, 2018 12:18 am

### Rounding

When figuring out the empirical ratio, what happens if you divide by the smallest number, and it doesn't come to a clear solution like 1: 1.333 : 1 ? In the pre-assessment question number 19, the ratio was 1 : 2.38 : 1 ? How do you handle this?

Jeffrey Xiao 4A
Posts: 35
Joined: Fri Sep 28, 2018 12:28 am
Been upvoted: 1 time

### Re: Rounding

.38 is extremely close to .4 so I thought of 2.38 as 2.4 then to turn 2.4 into a whole number you multiply it by 5 so 2.4(5) is 12
Ratio is then 5:12:5 since 5(1:2.38:1)~ 5:12:5.

marinhaluza_1
Posts: 15
Joined: Fri Sep 28, 2018 12:16 am

### Re: Rounding

I found it easy to turn the decimal into a fraction and seeing the number from that standpoint. For example, 1.33 is approximately 4/3 and in order to make that a whole number, you just need to multiply everything by 3!

Kessandra Ng 1K
Posts: 67
Joined: Fri Sep 28, 2018 12:25 am

### Re: Rounding

If it's something large like 2.38, or as long as it's not very near the whole number, I think you have to find another number to multiply it by. So if it's like 1.01 or 4.99 then it's fine to treat it as 1 and 5 respectively, but if it's 1.2 or 4.8 then you should definitely find another number to multiply it by!

Tamera Scott 1G
Posts: 65
Joined: Fri Sep 28, 2018 12:27 am

### Re: Rounding

I like the idea of turning the decimal into a fraction, it helps me know exactly what I need to multiply by to get a whole number!

Michelle Nwufo 2G
Posts: 61
Joined: Fri May 18, 2018 3:00 am

### Re: Rounding

What happens when you are dividing the given molar mass by the molar mass of the empirical formula in order to find the molecular formula and get a number like 2.18. Do i just round this to 2 and multiply the empirical formula by 2?

Michael Novelo 4G
Posts: 64
Joined: Fri Sep 28, 2018 12:28 am

### Re: Rounding

Michelle Nwufo 3A wrote:What happens when you are dividing the given molar mass by the molar mass of the empirical formula in order to find the molecular formula and get a number like 2.18. Do i just round this to 2 and multiply the empirical formula by 2?

Is there a certain problem you are referring to so we could see as reference? And if you're referring to the given molar mass (from mass spectrometry) and are dividing by the total molar mass of the empirical formula then it should be very close to 2 and not 2.18 since the Empirical Formula is giving us the relative ratio of atoms.