Question

PLEASE HELP!!!

Choose from the given list of aqueous solutions (A-D).

Solution A has [H3O+] = 3.5×10-5 M.
Solution B has [H3O+] = 3.5×10-4 M
Solution C has [OH-] = 1.3×10-10 M
Solution D has [OH-] = 6.2×10-11 M

Which solution is the least acidic?
Which solution has the highest pH?
Which solution is the most basic?
Which solution is the least basic?

Answer 1

Find pH of all

#A

pH=-log[H+]

• pH=-log[3.5×10^{-5}]
• pH=-log3.5+5
• pH=4.4

#B

• pH=-log3.5+4
• pH=3.4

#C

pOH=-log[OH]

• pOH=-log[1.3×10^{-10}]
• pOH=-log1.3+10
• 9.8

pH=

• 14-9.8
• 4.2

#4

• pOH=-log6.2+11
• pOH=10.2

pH

• 14-10.2
• 3.8

So our answers

1. solution A is least acidic
2. solution A has the highest pH
3. solution A is most basic
4. solution B is least basic