To calculate the molar mass of a compound, you add together the masses of all the atoms that make the compound. For example to calculate the molar mass of H_(2)O you add the mass of two hydrogen atoms to one oxygen atom. If you look on the periodic table, you will find that hydrogen's molar mass is 1.008g/mol and oxygen's molar mass is 15.999g/mol. To calculate the molar mass of H_(2)O you add (2times 1.008g/mol)+15.999g/mol for a total of 18.015g/mol. If you weigh 18 grams of water, you will have just under 6.022times 10^23 water molecules. Calculate the molar masses of the compounds below and show your work: 1. H_(2)O 6. C_(12)H_(22)O_(11) 2. KNO_(3) 7. C_(3)H_(8) 3. MgSO_(4) 8. NaOH 4. NH_(3) 9. Fe_(2)O_(3) 5. CaCO_(3) 10. AlPO_(4)

1. $H_{2}O$<br />To calculate the molar mass of $H_{2}O$, we need to add the masses of all the atoms in the compound.<br /><br />The molar mass of hydrogen (H) is 1.008 g/mol, and there are two hydrogen atoms in $H_{2}O$. The molar mass of oxygen (O) is 15.999 g/mol.<br /><br />So, the molar mass of $H_{2}O$ is:<br />$(2 \times 1.008 \, \text{g/mol}) + 15.999 \, \text{g/mol} = 18.015 \, \text{g/mol}$<br /><br />2. $KNO_{3}$<br />The molar mass of potassium (K) is 39.10 g/mol, the molar mass of nitrogen (N) is 14.007 g/mol, and the molar mass of oxygen (O) is 999 g/mol. There are three oxygen atoms in $KNO_{3}$.<br /><br />So, the molar mass of $KNO_{3}$ is:<br />$39.10 \, \text{g/mol} + 14.007 \, \text{g/mol} + (3 \times 15.999 \, \text{g/mol}) = 101.103 \, \text{g/mol}$<br /><br />3. $MgSO_{4}$<br />The molar mass of magnesium (Mg) is 24.305 g/mol, the molar mass of sulfur (S) is 32.06 g/mol, and the molar mass of oxygen (O) is 15.999 g/mol. There are four oxygen atoms in $MgSO_{4}$.<br /><br />So, the molar mass of $MgSO_{4}$ is:<br />$24.305 \text{g/mol} + 32.06 \, \text{g/mol} + (4 \times 15.999 \, \text{g/mol}) = 120.366 \, \text{g/mol}$<br /><br />4. $NH_{3}$<br />The molar mass of nitrogen (N) is 14.007 g/mol, and the molar mass of hydrogen (H) is 1.008 g/mol. There are three hydrogen atoms in $NH_{3}$.<br /><br />So, the molar mass of $NH_{3}$ is:<br />$14.007 \, \text{g/mol} + (3 \times 1.008 \, \text{g/mol}) = 17.031 \, \text{g/mol}$<br /><br />5. $CaCO_{3}$<br />The molar mass of calcium (Ca) is 40.078 g/mololar mass (C) is 12.011 g/mol, and the molar mass of oxygen (O) is 15.999 g/mol. There are three oxygen atoms in $CaCO_{3}$.<br /><br />So, the molar mass of $CaCO_{3}$ is:<br />$40.078 \, \text{g/mol} + 12.011 \, \text{g/mol} + (3 \times 15.999 \, \text{g/mol}) = 100.086 \, \text{g/mol}$<br /><br />6. $C_{12}H_{22}O_{11}$<br />The molar mass of carbon (C) is 12.011 g/mol, the molar mass of hydrogen (H) is 1.008 g/mol, and the molar mass of oxygen (O) is.999 g/mol. There are twelve carbon atoms, twenty-two hydrogen atoms, and eleven oxygen atoms in $C_{12}H_{22}O_{11}$.<br /><br />So, the molar mass of $C_{12}H_{22}O_{11}$ is:<br />$(12 \times 12.011 \, \text{g/mol}) + (22 \times 1.008 \, \text{g/mol}) + (11 \times 15.999 \, \text{g/mol}) = 342.297 \, \text{g/mol}$<br /><br />7. $C_{3}H_{8}$<br />The molar mass of carbon (C) is 12.011 g/mol, and the molar mass of hydrogen (H) is 1.008 g/mol. There are three carbon atoms and eight hydrogen atoms in $C_{3}H_{8}$.<br /><br />So, the molar mass of $C_{3}H_{8}$ is:<br />$(3 \times 12.011 \, \text{g/mol}) + (8 \times 1.008 \, \text{g/mol}) = 44.097 \, \text{g/mol}$<br /><br />8. NaOH<br />The molar mass of sodium (Na