Question #ad51c
1 Answer
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
#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%" ")|)#