## Question from textbook

Any general non-science questions (software questions/problems, etc.,) and class announcements.

Riya Shah 4H
Posts: 65
Joined: Wed May 02, 2018 3:00 am

### Question from textbook

A student prepared a solution of sodium carbonate by adding 2.111 g of the solid to a 250.0-mL volumetric flask and adding water to the mark. Some of this solution was transferred to a buret. What volume of solution should the student transfer into a flask to obtain (a) 2.15 mmol Na+; (b) 4.98 mmol CO3^2-; (c) 50.0 mg Na2CO3?

Albert_Luu3K
Posts: 62
Joined: Fri Sep 28, 2018 12:23 am

### Re: Question from textbook

First, use the 2.111g Na2CO3 and the 250.0mL and find the molarity. I got .07980mol/L.
For part a, take the 2.15mmol Na+ ion and convert into moles. There are two Na+ ion per Na2CO3 molecule, so using dimensional analysis you find out how many moles of Na2CO3 you need. Using the molarity we found, we can convert that into how many liters of the solution we need.
Using this process, you can find part b and part c. It's just a lot of dimensional analysis.

Yixiao Hu 3C
Posts: 45
Joined: Fri Sep 28, 2018 12:19 am

### Re: Question from textbook

Use 2.111g Na2CO3 and the 250.0mL to get the molarity. 0.08mol/L.
Take the 2.15mmol Na+ ion and convert into moles. There are two Na+ ion per Na2CO3 molecule. Using the molarity, we can convert that into how many liters of the solution we need.
you can find the answers for part c by the same way