Answer
a) $10.17\ m$
b) $37.08\%$
Work Step by Step
a)
In 1 liter of solution:
$12.0\ M\times 1.0\ L=12.0\ mol$
Mass of solution:
$1.0\ L\times 1.18\ g/cm^3\times 1000\ cm^3/L=1180\ g=1.18\ kg$
Molality of solution:
$12.0\ mol\div 1.18\ kg=10.17\ m$
b) Mass of HCl:
$12.0\ mol\times36.46\ g/mol=437.52\ g$
Weight percent:
$437.52\div 1180\times 100\%=37.08\%$
