Question

in round numbers of daltons, sucrose has a molecular mass of daltons. because we can’t weigh out small numbers of molecules, we usually measure substances in units called moles. just as dozen always means 12 objects, a mole (mol) represents an exact number of objects: which is called avogadro’s number. because of the way in which avogadro’s number and the unit dalton were originally defined, once we determine the molecular mass of a molecule such as sucrose, we can use the same number, but with the unit gram, to represent the mass of molecules of sucrose, or 1 mol of sucrose (sometimes called the molar mass). (for example, o has a mass of 16. therefore, one mole of o has a mass of 16 x 11 = 176 g/mole.)

c. add the masses of each element in the molecule to get the molar mass of sucrose.

to obtain 1 mol of sucrose in the lab, therefore, we weigh out 342 g.
how would we make a liter (l) of solution consisting of 1 mol of sucrose dissolved in water? we would measure out ____ g of sucrose and then gradually add water, while stirring, until the sugar was completely dissolved. we would then add enough water to bring the total volume of the solution up to 1 l. at that point, we would have a 1 - molar (1 m) solution of sucrose.

Explanation:

Step1: Recall molar - mass concept

The molar mass of a substance is the mass of 1 mole of that substance. It is given that to obtain 1 mol of sucrose in the lab, we weigh out 342 g.

Step2: Determine mass for 1 - molar solution

A 1 - molar (1 M) solution contains 1 mole of solute per liter of solution. Since 1 mole of sucrose has a mass of 342 g, to make 1 L of a 1 - molar solution of sucrose, we need 342 g of sucrose.

Answer:

342