## Module: Molarity #15

Mariam Baghdasaryan 4F
Posts: 37
Joined: Fri Sep 28, 2018 12:29 am

### Module: Molarity #15

15. Calculate the concentration (molarity) of a glucose solution containing 0.1 moles of glucose in 0.4 liters of water.
A. 0.25 mol.L-1
B. 4.0 mol.L-1
C. 2.5 mol.L-1
D. 2 mol.L-1

.1mol/.4L=.25 mol. L-1. So I got this for the answer but I was confused why the answer is exact and not 1 sig fig (.2)

jonathanjchang2E
Posts: 61
Joined: Fri Sep 28, 2018 12:26 am

### Re: Module: Molarity #15

I don't think multiple choice questions are as stringent on significant figures.

Tony Ong 3K
Posts: 63
Joined: Fri Sep 28, 2018 12:23 am

### Re: Module: Molarity #15

That is strange! I would say to always keep the habit of putting the correct sig figs regardless because it's 1 point off per question on the midterms and finals!

Courtney Quan 1C
Posts: 60
Joined: Fri Sep 28, 2018 12:26 am
Been upvoted: 2 times

### Re: Module: Molarity #15

I'm not sure either, but I refer back to the given information of the problem when determining the number of significant figures in my answer. You shouldn't have more significant figures in your answer than was present in the information with the least number of significant figures in the question. At least you got the answer right!

Rachana Jayaraman 1H
Posts: 61
Joined: Fri Sep 28, 2018 12:26 am

### Re: Module: Molarity #15

On the actual test you would round 0.25 to 0.2 because of sig figs, but I think that the answer is 0.25 on this question is to prevent confusion since people may not be considering sig figs while taking the assessment.

Joussie Camacho 4I
Posts: 33
Joined: Tue Oct 02, 2018 12:16 am

### Re: Module: Molarity #15

You wouldn't round up to 0.3?

Courtney McHargue 1I
Posts: 56
Joined: Fri Sep 28, 2018 12:17 am

### Re: Module: Molarity #15

Since 0.25 isn't followed by any other decimal values after the 5, normally this answer would and should be rounded to 0.2 since both of the values getting you to this answer had only one significant figure.