× Didn't find what you were looking for? Ask a question
Top Posters
Since Sunday
a
5
k
5
c
5
B
5
l
5
C
4
s
4
a
4
t
4
i
4
r
4
r
4
Home Q & A Board Science-Related Homework Help Chemistry (Moderator: Laser_3)
New Topic  
smita smita
wrote...
Posts: 17
Rep: 0 0
11 years ago
An unknown monoprotic acid has a molar mass of 84.0 g/mol. When 9.70 g of the acid is dissolved in 1.000 L of water, the pH of the solution is 2.780. What is the pKa of the unknown acid?
Read 520 times
1 Reply

Related Topics

Replies
wrote...
#1
11 years ago
moles HA = 9.70 / 84.0 =0.115
initial concentration HA = 0.115 / 1.00 L = 0.115
concentration H+ = 10^-2.780=0.00166 M = concentration A-
concentration HA at equilibrium = 0.115 - 0.00166 =0.113
Ka = ( 0.00166)^2 / 0.113 =0.0000244
New Topic      
Quick Reply
Explore
Post your homework questions and get free online help from our incredible volunteers
  908 People Browsing
Start New Topic Take the Tour CoursesNew Study Tools Topics Trending Browse by Textbook
Live Chat
Related Images
  
 128
  
 222
  
 58
Your Opinion
Where do you get your textbooks?
Votes: 328
Previous poll results: What's your favorite math subject?