Calculate the concentration in Moles for a 5mgMgCl2 sample in 2L of solution. Then how many ions are in it?
To calculate the concentration in moles for a sample, you need to divide the mass of the substance by its molar mass.
1. Determine the molar mass of MgCl2:
- The atomic mass of Mg is approximately 24.31 g/mol.
- The atomic mass of Cl is approximately 35.45 g/mol.
- Since MgCl2 has one Mg atom and two Cl atoms, the molar mass of MgCl2 would be:
(1 * 24.31) + (2 * 35.45) = 95.21 g/mol.
2. Calculate the moles of MgCl2:
- Given that you have a 5 mg (0.005 g) sample of MgCl2.
- Divide the mass of the sample by the molar mass of MgCl2:
Moles = Mass / Molar mass
Moles = 0.005 g / 95.21 g/mol
This will give you the concentration in moles.
To find out the number of ions in the sample of MgCl2, you need to multiply the number of moles by the number of ions produced by one unit of the substance.
3. Determine the number of ions produced by one unit of MgCl2:
- MgCl2 dissociates into one Mg2+ ion and two Cl- ions.
4. Calculate the number of ions:
- Multiply the moles of MgCl2 by the number of ions produced by one unit:
Number of ions = Moles of MgCl2 * (1 + 2)
This will give you the total number of ions in the sample.