Answer:
To convert from mols to grams, multiply the number by the total molar mass of the compound.
To find the approximate molar mass of a compound, add up the molar masses of each element in the compound, making sure to multiply by the subscripts.
#2 for example:
First, find the molar mass of NaCl.
Molar mass of Na= 22.990g (refer to a periodic table or look it up)
Molar mass of Cl= 35.45g
22.990g + 35.45g= 58.44g
Next, convert from mols to g.
2.19 mol x 58.44g= 127.98g NaCl
To convert from grams to mols, do the same thing as mols to grams except DIVIDE instead of multiply.
#3 for example:
NaC2H3O2
Na= 22.99g
C2= 12.011 x 2 => 24.022g (multiply molar mass of C by 2 since there are 2 carbons)
Do this for the rest of the elements in the compound and add them up. The total molar mass should be approximately 82.0343g.
Next, convert from g to mol.
14.68g/82.0343g≈ 0.179 mol