× Didn't find what you were looking for? Ask a question
Top Posters
Since Sunday
k
4
c
4
M
3
t
3
i
3
B
3
k
3
m
3
c
3
o
3
l
3
r
3
Home Q & A Board Laboratory Help Introductory Courses
New Topic  
feven feven
wrote...
Posts: 13
Rep: 0 0
11 years ago
Given that 20.00 mL of phosphoric acid solution required 15.50 mL of 0.200M
NaOH for the first equivalent point. What is the molarity of the phosphoric acid?
Read 1400 times
2 Replies

Related Topics

Replies
wrote...
#1
11 years ago
Use the formula:-
M1V1=M2V2
M1= molarity of 1st solution
V1= volume of 1st solution
M2= molarity of 2nd solution
V2= volume of 2nd solution
Here,
M1= ?
V1= 20mL
M2= .2 M
V2= 15.50mL
Putting in values we get,
M1*20 = .2*15.5
M1= .2*15.5/20 = .155M
So the molarity of phosphoric acid is 0.155M
wrote...
#2
11 years ago
NaOH + H3PO4 = NaH2PO4 + H20
The first equivalent point
Mol(NaOH) = 0.2 x 15.5  / 1000 =>
Mol(NaOH) = 0.0031 mol
Since this number of moles NaOH gives NaH2PO4
Then moles of NaH2PO4 used is 0.0031
Molarity (H3PO4) = 0.0031 x 1000 / 20.0 = 0.155M
New Topic      
Quick Reply
Explore
Post your homework questions and get free online help from our incredible volunteers
  899 People Browsing
Start New Topic Take the Tour CoursesNew Study Tools Topics Trending Browse by Textbook
Live Chat
Related Images
  
 230
  
 862
  
 113
Your Opinion
What's your favorite coffee beverage?
Votes: 299
Previous poll results: Which of the following is the best resource to supplement your studies: