Question #ad51c

1 Answer
Aug 14, 2017

Answer:

#%"mass glucose" = 17.4%#

Explanation:

We're asked to find the percent by mass of glucose, given how much is dissolved in a known amount of water.

The formula for mass percentage of a substance #x# is given by

#ulbar(|stackrel(" ")(" "%"mass"color(white)(l)x = ("mass of"color(white)(l)x)/("total mass") xx 100%" ")|)#

(Here, #x# represents glucose.)

The total mass of the solution is the mass of the *glucose plus the mass of *water:

#"total mass" = overbrace(156color(white)(l)"g")^"glucose" + overbrace(740color(white)(l)"g")^"water" = color(red)(ul(896color(white)(l)"g"#

The mass percentage of glucose is therefore

#color(blue)(%color(white)(l)"mass glucose") = (156color(white)(l)"g glucose")/(color(red)(896color(white)(l)"g solution")) xx 100% = color(blue)(ulbar(|stackrel(" ")(" "17.4%" ")|)#