What is the formula mass, in amu, of KNaC4H4O6·4H2O? Be sure to include the water molecules
To calculate the formula mass, we need to sum the atomic masses of all the atoms in the compound.
The compound KNaC4H4O6·4H2O consists of the following elements:
- K (potassium)
- Na (sodium)
- C (carbon)
- H (hydrogen)
- O (oxygen)
The atomic masses of these elements, rounded to two decimal places, are as follows:
- K: 39.10 amu
- Na: 22.99 amu
- C: 12.01 amu
- H: 1.01 amu
- O: 16.00 amu
In addition, there are four water molecules (4H2O). Each water molecule consists of two hydrogen atoms and one oxygen atom. We can find the atomic mass of water by adding the atomic masses of its constituent elements:
- H2O:
- H: 2 * 1.01 amu = 2.02 amu
- O: 1 * 16.00 amu = 16.00 amu
Adding up the atomic masses of the compound:
- KNaC4H4O6:
- K: 39.10 amu
- Na: 22.99 amu
- C4H4O6:
- C: 4 * 12.01 amu = 48.04 amu
- H: 4 * 1.01 amu = 4.04 amu
- O: 6 * 16.00 amu = 96.00 amu
- Total for KNaC4H4O6: 39.10 amu + 22.99 amu + 48.04 amu + 4.04 amu + 96.00 amu = 210.17 amu
- 4H2O:
- H2O: 18.02 amu
- Total for 4H2O: 4 * 18.02 amu = 72.08 amu
Now, we can sum the masses of KNaC4H4O6 and 4H2O:
- KNaC4H4O6·4H2O: 210.17 amu + 72.08 amu = 282.25 amu
Therefore, the formula mass of KNaC4H4O6·4H2O is 282.25 amu.
To find the formula mass of KNaC4H4O6·4H2O, we need to determine the atomic masses of all the elements present in the compound and then add them up.
Here’s a step-by-step breakdown:
1. Find the atomic mass of each element in the compound:
- K (potassium) has an atomic mass of 39.10 amu.
- Na (sodium) has an atomic mass of 22.99 amu.
- C (carbon) has an atomic mass of 12.01 amu.
- H (hydrogen) has an atomic mass of 1.01 amu.
- O (oxygen) has an atomic mass of 16.00 amu.
2. Calculate the total atomic mass for each element, accounting for the subscripts as well as the water molecules:
- For KNaC4H4O6:
- K: 1 atom × 39.10 amu = 39.10 amu
- Na: 1 atom × 22.99 amu = 22.99 amu
- C: 4 atoms × 12.01 amu = 48.04 amu
- H: 4 atoms × 1.01 amu = 4.04 amu
- O: 6 atoms × 16.00 amu = 96.00 amu
- For 4H2O (water molecules):
- H: 8 atoms × 1.01 amu = 8.08 amu
- O: 4 atoms × 16.00 amu = 64.00 amu
3. Add up the total atomic masses of all elements:
- KNaC4H4O6: 39.10 amu + 22.99 amu + 48.04 amu + 4.04 amu + 96.00 amu = 210.17 amu
- 4H2O: 8.08 amu + 64.00 amu = 72.08 amu
4. Finally, add the total atomic masses of both compounds to get the formula mass:
- Formula mass = 210.17 amu + 72.08 amu = 282.25 amu
Therefore, the formula mass of KNaC4H4O6·4H2O is 282.25 amu