An ammonia solution is 6.00 M and the density is 0.950 g/mL. What is the mass/mass percent concentration of #NH_3# (17.04 g/mol)?

1 Answer
Sep 29, 2016

Approx. #10-11%#

Explanation:

We want to find the quotient: #"mass of ammonia"/"mass of solution"xx100%#.

We know (i) that #"moles of ammonia"/"volume of solution"# #=# #6.00*mol*L^-1#.

We know (ii) that #"mass of solution"/"volume of solution"# #=# #0.950*g*mL^-1#.

From (i) we know that a #1*L# volume of solution contains:

#1*Lxx6.00*mol*L^-1xx17.03*g*mol^-1# #=# #102.18*g" ammonia"#

From (ii) we know that, #1*L# of solution has a mass of #0.950*g*mL^-1xx1000*mL# #=# #950.0*g#.

And thus #"mass of ammonia"/"mass of solution"xx100%# #=#

#(102.18*g)/(950*g)xx100%~=11%# Whewww, arithmetic!!