What is the variable x in the following hydrate formula NaCl xH2O if the mass of sodium chloride is 58g and the mass of the water is 36g
To find the variable 'x' in the hydrate formula NaCl x H2O, we need to use the given information about the masses of sodium chloride (NaCl) and water (H2O).
The formula for a hydrate consists of two parts: the anhydrous (without water) compound, in this case, sodium chloride (NaCl), and the water molecules (H2O) attached to it.
Let's assign a variable, 'x', to represent the number of water molecules (H2O) present in the hydrate formula NaCl x H2O.
Given:
Mass of sodium chloride (NaCl) = 58g
Mass of water (H2O) = 36g
Since the molar mass of NaCl is 58.5 g/mol, we can assume that there is one mole of NaCl present in the compound.
To find the number of moles of water (H2O), we need to convert the mass of H2O into moles. The molar mass of water is 18g/mol.
Number of moles of H2O = Mass of H2O / Molar mass of H2O
= 36g / 18g/mol
= 2 moles
Now, we know that the molar ratio between NaCl and H2O is 1:1 in the hydrate formula. Therefore, the number of moles of NaCl is also 2.
The formula for moles can be represented as follows:
Mol
To find the variable x in the hydrate formula NaCl xH2O, you need to calculate the molar mass of sodium chloride (NaCl) and water (H2O).
1. Find the molar mass of NaCl:
- Sodium (Na) has a molar mass of 22.99 g/mol.
- Chlorine (Cl) has a molar mass of 35.45 g/mol.
- Add the molar mass of Na and Cl: 22.99 g/mol + 35.45 g/mol = 58.44 g/mol.
2. Calculate the number of moles of NaCl:
- Divide the mass of NaCl (58g) by its molar mass:
58g / 58.44 g/mol = 0.993 mol.
3. Find the moles of water (H2O):
- Divide the mass of water (36g) by its molar mass:
36g / 18.02 g/mol = 1.999 mol.
4. Finally, compare the ratio of NaCl to H2O:
- Divide the moles of NaCl by the moles of water:
0.993 mol / 1.999 mol ≈ 0.497.
- The variable x is approximately 0.497.
- So, the hydrate formula is NaCl 0.497H2O.