Question #32a07

1 Answer
Mar 8, 2016

Answer:

#C=0.2#mol/#dm^3#

Explanation:

the molar concentration C is defined as : #C=n/V#
n : amount of solute and V : Volume

we know that #n=m/M#
m : masse of the solute and M : Molar mass

the concentration will be #C=m/(M*V)#
in your exemple #V=500 cm^3 = 0.5dm^3#

M for Sodium Hydroxide NaOH is
#M=M(Na)+M(O)+M(H)#
#=22.98976+15.9994+1.00794=39.9971# g/mol

#m=4g#
so #C=4/(39.9971*0.5)=0.2#mol/#dm^3#