Calculate the mass in grams of 0.250 mol of each of the following compounds

mass-in-grams

#1

Calculate the mass in grams of 0.250 mol of each of the following compounds:

a. sucrose (C12H22O11)
b. sodium chloride (NaCl)
c. potassium permanganate (KMnO4)

Answer:

Molar mass and moles to grams calculator:

a.) The formula for converting moles to mass (grams) is:
[mol amount of substance]*gfm (mass of one mol of the substance)/1 mol of substance = grams of substance

Here, you are converting 0.250 mol of C12H22O11 to mass, so the formula filled out is:
0.250 mol C12H22O11 * gfm C12H22O11 / 1 mol C12H22O11 = grams of substance

To find the gram formula mass of sucrose, we need to add up the gram atomic masses (mass of 1 mol of the element) of the particles making up sucrose. You can get the gram atomic mass of an element from the periodic table by looking at the atomic mass; the mass of 1 mol of an element has the same number of the atomic mass, but in grams.

gfm C12H22O11 = (1212.0) + (221.0)+(11*16.0) = 342 g

Now we use this information to complete the formula.

0.250 mol C12H22O11 * 342 g C12H22O11 / 1 mol C12H22O11 = 85.5 g C12H22O11

The answer is 85.5 g sucrose.

b.) We use the same procedure stated in problem a. For simplicity’s sake, let’s let B represent the chemical formula of the substance in question, NaCl.

Formula: mol B * gfm B / 1 mol B = grams B

0.250 mol NaCl * gfm NaCl / 1 mol NaCl = grams NaCl

Calculate the gfm of NaCl: 23.0 + 35.5 = 58.5 g

Back to the formula: 0.250 mol NaCl * 58.5 g NaCl / 1 mol NaCl = 14.6 g NaCl

The answer is 14.6 g sodium chloride.

c.) Same process as the one we’ve used in a and b.

Formula: mol B * gfm B / 1 mol B = grams B

0.250 mol KMnO4 * gfm KMnO4 / 1 mol KMnO4 = grams KMnO4

gfm of KMnO4: 39.1 + 54.9 + (4 * 16.0) = 158 g KMnO4

0.250 mol KMnO4 * 158 g KMnO4 / 1 mol KMnO4 = 39.5 g KMnO4

The answer is 39.5 g potassium permanganate.