This is a dilution problem on a practice test that I am having trouble with:
Concentrated sulfuric acid is 18 M. What volume of water would be needed to dilute 25 mL of concentrated H2SO4 solution to 3 M?
A. 25 mL
B. 50 mL
C. 75 mL
D. 125 mL
E. 150 mL
I used MiVi = MfVf
So: (18 M)(25 mL) = (3 M)(x)
x = 150 mL
*but the answer key says 125 mL is the right answer. Is this a mistake or am I missing something? Maybe it has something to do with the molar equivalents (2H's that dissociate from sulfuric acid)...I don't know.
Also:
Which of the following is the electron configuration of Mn2+?
A. [Ar]4s2 3d5
B. [Ar]3d5
C. [Ar]4s2 3d5
D. [Ar]3d3
E. [Ar]4s2 3d7
I got C. but the key says B.
Help please!
Thanks
Concentrated sulfuric acid is 18 M. What volume of water would be needed to dilute 25 mL of concentrated H2SO4 solution to 3 M?
A. 25 mL
B. 50 mL
C. 75 mL
D. 125 mL
E. 150 mL
I used MiVi = MfVf
So: (18 M)(25 mL) = (3 M)(x)
x = 150 mL
*but the answer key says 125 mL is the right answer. Is this a mistake or am I missing something? Maybe it has something to do with the molar equivalents (2H's that dissociate from sulfuric acid)...I don't know.
Also:
Which of the following is the electron configuration of Mn2+?
A. [Ar]4s2 3d5
B. [Ar]3d5
C. [Ar]4s2 3d5
D. [Ar]3d3
E. [Ar]4s2 3d7
I got C. but the key says B.
Help please!
Thanks