How many moles of HBr are present in 18. mL of a 0.400 M solution?

1 Answer
May 12, 2017

Answer:

Approx. #7*mmol#

Explanation:

#"Molarity"# is defined by the quotient,............

#"Molarity"="Moles of solute"/"Volume of solution"#, .................

and thus the product...................

#"Volume of solution"xx"molarity"="moles of solute"#

And so #"moles of HBr"=18xx10^-3*cancelLxx0.400*mol*cancel(L^-1)=#

#=7.20xx10^-3*mol#, with respect to #HBr#.

The product is dimensionally consistent; we wanted an answer in moles, and the product gave us an answer in moles. This is good indication that we set the problem up correctly.