Question #2e157

1 Answer
Dec 13, 2015

Answer:

Dissolve 2.25 grams of glucose in 250 milliliters solvent.

Explanation:

To get the weight of glucose to be dissolved in solvent (usually water), first you must do the following computations:

(1) Convert the given volume from milliliters (mL) to liters (L).

#250 cancel "mL"# x #"1 L"/(1000 cancel "mL")# = #"0.250 L"#

(2) Convert the given number of Liters to number of moles (mol) using the given molar concentration (unit is moles per Liter solution).

#0.250 cancel "L"# x #(0.05 "mol")/(1 cancel "L")# = #"0.0125 mol"#

(3) Convert computed number of moles to number of grams (g) using the molecular weight of the substance.

#0.0125 cancel "mol"# x #(180 g)/(1 cancel "mol")# = #"2.25 g"#

Therefore, in order to get a 0.05 molar solution, you must dissolve 2.25 grams of glucose in 250 milliliters solvent.

Here is a video that explains in details how to prepare a solution in the lab:
Lab Demonstration | Solution Preparation & Dilution.