Calculate these problems?

Question

Calculate the moles for 32.0 grams of SO2

Calculate the mass in grams of 0.602 moles of Ca(NO3)2 . 3H20

Calculate the moles of 1.50x10 to the 23rd molecules of NH3

Calculate the mass of 2.41 x 10 to the 24th molecules of H2O

Calculate the number of molecules for 68.0 grams of H2S

Calculate the percent of composition of HCN

THANKS SO MUCH!!

Answer 1

To change grams to moles, divide by the molecular mass

To change moles to grams, multiply by the molecular mass

To change molelcules to moles divide by 6.022 x 10^23

To change molecules to mass, first change to moles then to grams(see above)

To change grams to molecules, first change to moles then to molecules (see above)

(molecular mass is the mass you get when you add up the individual atomic masses).

To calculate %composition:

1. Add up the individual atomic masses to get the total mass
2. For each element take its individual mass and divide it by the total you just calculated; multiply by 100 to change to %