Test 1, Q1  [ENDORSED]

Moderators: Chem_Mod, Chem_Admin

Brynne Keyser 1B
Posts: 31
Joined: Fri Apr 06, 2018 11:03 am

Test 1, Q1

Postby Brynne Keyser 1B » Sat May 05, 2018 2:07 pm

If someone could walk me through this problem, it would be much appreciated!

A) Lithium carbonate, Li2CO3, is a salt that is used for the treatment of bipolar disorder. A solution of lithium carbonate is prepared by dissolving 2.0 g of salt to 1.00 L water. What is the concentration of lithium ions for the above solution?

B) The above solution is diluted with 1.00 L of 0.100 M of lithium chloride, LiCl, solution. What is the concentration of lithium ions after the dilution?

Thanks in advance!

Alejandro Salazar 1D
Posts: 31
Joined: Fri Sep 29, 2017 7:05 am

Re: Test 1, Q1

Postby Alejandro Salazar 1D » Sat May 05, 2018 2:23 pm

For part A, did you get M= 73.9. I'm not sure if I did correctly either. I simply used M= n(number of moles)/V(Liters)

Emely Reyna 1F
Posts: 30
Joined: Fri Apr 06, 2018 11:04 am

Re: Test 1, Q1  [ENDORSED]

Postby Emely Reyna 1F » Sun May 06, 2018 10:43 pm

For part B to find the concentration of the lithium ions you find the moles from the previous question and add the 0.100 mols from the new solution. You then divide by the total volume, which in this problem would be 2.00 L.

Posts: 45
Joined: Fri Apr 06, 2018 11:04 am

Re: Test 1, Q1

Postby SammiOrsini_1B » Tue May 08, 2018 10:49 am

For part A of the question I got .054 M. This number is extremely different from the one above. If anyone knows how to do this problem could they please walk me through it. I found the molar mass of the salt and got 73.892 g/mol and I found that there are .054 mol of Li in the solution. I then divided the .o54 by 1 L and got .054 M.

Posts: 18400
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 435 times

Re: Test 1, Q1

Postby Chem_Mod » Tue May 08, 2018 4:05 pm

Make sure to find the number of moles of Li+ for part A, which is twice the number of moles of Li2CO3

Return to “Molarity, Solutions, Dilutions”

Who is online

Users browsing this forum: No registered users and 3 guests