Calculate the molar mass of potassium hydroxide (KOH). How many atoms
would we find in a 100 mL solution of 1 µM KOH?
0.1 L * 1µ mole/L = 10^-7 moles = 6.02 * 10^16 molecules.
If you want atoms of solute, then that would be 3 times as many.
If you also want to include the H2O, then you need to add the 100ml of H2O to the mix.
To calculate the molar mass of potassium hydroxide (KOH), we need to find the atomic masses of each element in the compound and sum them up.
The atomic mass of potassium (K) is 39.10 g/mol.
The atomic mass of oxygen (O) is 16.00 g/mol.
The atomic mass of hydrogen (H) is 1.01 g/mol.
Now, let's calculate the molar mass of KOH:
Molar mass of KOH = (atomic mass of K) + (atomic mass of O) + (atomic mass of H)
= (39.10 g/mol) + (16.00 g/mol) + (1.01 g/mol)
= 56.11 g/mol
So, the molar mass of potassium hydroxide (KOH) is 56.11 g/mol.
To find the number of atoms in a 100 mL solution of 1 µM (micromolar) KOH, we need to use Avogadro's number and the molar concentration.
Avogadro's number (Nᴀ) is approximately 6.022 x 10^23 atoms/mol.
Given:
Molar concentration (C) = 1 µM = 1 x 10^(-6) M
Volume (V) = 100 mL = 100 x 10^(-3) L
Now, let's calculate the number of atoms:
Number of atoms = (Molar concentration) x (Volume) x (Avogadro's number)
= (1 x 10^(-6) mol/L) x (100 x 10^(-3) L) x (6.022 x 10^23 atoms/mol)
= (1 x 10^(-8) mol) x (6.022 x 10^23 atoms/mol)
= 6.022 x 10^15 atoms
So, there would be approximately 6.022 x 10^15 atoms in a 100 mL solution of 1 µM KOH.