The Ksp for BaF2 is 2.4 x 10-5. When 10 mL of 0.01 M NaF is mixed with 10 mL of 0.01 M BaNO3, will a precipitate form?

A precipitate will not occur.

Explanation:

2NaF + Ba(NO3)2 --> BaF2 + 2NaNO3

NaF --> Na+ + F-

Ba(NO3)2 --> Ba2+ + 2NO3-

Number of moles of F- = 0.010 x 0.01

= 0.00010 mol

Number of moles of Ba2+ = 0.010 L x 0.01 M

= 0.00010 mol

total volume = 0.020 L

[F-] = [Ba2+]

= 0.00010/ 0.020

= 0.0050 M

Qsp = [Ba2+] . [F-]^2

= 0.0050 * (0.0050)^2

= 1.2 x 10^-7 < Ksp

A precipitate will not occur.

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.