How many #sf(OH^-)# ions are present in 5.0 ml of 0.3M #sf(Ba(OH)_2)# solution ?

1 Answer
Sep 26, 2015

#1.8xx10^21#

Explanation:

1 mole barium hydroxide produces 2 moles hydroxide ions:

#rarrBa_((aq))^(2+)+2OH_((aq))^-#

#c=n/v#

#n=cxxv#

so no. moles #OH^(-) = 2xx0.3xx0.005=0.003"mol"#

Multiplying by #L# The Avogadro Constant:

#=6.02xx10^(23)xx0.003=1.8xx10^(21)# ions.

This ignores the small amount present from the ionisation of water.