3.22g of hydrated sodium sulphate, Na2SO4 X H2O were hearted to a constant mass of
1.42 g. Determine the value of x in the formula ( Na=23.0, s = 32.0, O = 16, H = 1)
3.22 g = Na2SO4.xH2O before heating
-1.42 g = Na2SO4.xH2O after heating
----------------------------
1.80 g = mass H2O expelled.
Convert to mols.
mols Na2SO4 = g/molar mass = 1.42/142 = 0.01
mols H2O = 1.80/18 = 0.1
Now find the ratio of Na2SO4 to H2O. The easy way to do this is to divide both number of the smaller number; i.e.,
mols Na2SO4 = 0.01/0.01 = 1
mols H2O = 0.1/0.01 = 10.
Formula is Na2SO4.10H2O
have no idea
Oh, so we have a little chemistry question here! Let me put on my lab coat... Just kidding, I don't have a lab coat. But I can still help you solve this!
So, we start with 3.22g of hydrated sodium sulphate, Na2SO4 X H2O. After heating it, we're left with a constant mass of 1.42g. We need to find the value of x in the formula.
Since we're dealing with hydrated sodium sulphate, we know that there is a certain amount of water, H2O, attached to each formula unit of Na2SO4. The question is asking for the value of x, which represents the number of water molecules per formula unit.
So, let's calculate the difference in mass:
Initial mass - Final mass = mass of water lost
3.22g - 1.42g = 1.80g of water lost
Now, we'll calculate the molar mass of water (H2O):
Molar mass of H2O = 2(1.008 g/mol) + 16.00 g/mol = 18.016 g/mol
Next, we'll calculate the moles of water lost:
Moles = mass / molar mass
Moles of water lost = 1.80g / 18.016 g/mol = 0.0999 mol
Since our formula is Na2SO4 X H2O, we know that there is one mole of water per mole of Na2SO4. So, the value of x is 1.
Hope that helps, and remember, chemistry can be a real gas!
To find the value of x in the formula Na2SO4 · xH2O, we need to calculate the amount of water that was lost during heating.
First, let's calculate the molar mass of Na2SO4:
Na = 23.0 g/mol
S = 32.0 g/mol
O = 16 g/mol (there are 4 oxygen atoms in Na2SO4)
Molar mass of Na2SO4 = (2 * 23.0) + 32.0 + (4 * 16) = 142 g/mol
Next, let's calculate the number of moles of Na2SO4:
Number of moles of Na2SO4 = mass / molar mass
Number of moles of Na2SO4 = 1.42 g / 142 g/mol
Number of moles of Na2SO4 = 0.01 mol
Since Na2SO4 and xH2O are in a 1:1 ratio, the number of moles of water lost is also 0.01 mol.
Now, let's calculate the mass of water lost during heating:
Mass of water lost = moles of water lost * molar mass of water
Mass of water lost = 0.01 mol * (2 * 1.008 + 16) g/mol
Mass of water lost = 0.01 mol * 18.016 g/mol
Mass of water lost = 0.18016 g
Finally, to find the value of x, we need to subtract the mass of water lost from the initial mass of the hydrated sodium sulfate:
x = initial mass - mass of water lost
x = 3.22 g - 0.18016 g
x = 3.04 g
Therefore, the value of x in the formula Na2SO4 · xH2O is 3.04.
To determine the value of x in the formula Na2SO4 x H2O, we can use the concept of molar masses and the Law of Conservation of Mass.
First, let's calculate the molar mass of hydrated sodium sulphate (Na2SO4 x H2O). To do this, we need to find the molar mass of each element and multiply it by the subscript (or coefficient) that represents the number of atoms of each element in the formula.
The molar mass of sodium (Na) = 23.0 g/mol
The molar mass of sulfur (S) = 32.0 g/mol
The molar mass of oxygen (O) = 16.0 g/mol
The molar mass of hydrogen (H) = 1.0 g/mol
For Na2SO4, we have:
2 x Na = 2 x 23.0 g/mol = 46.0 g/mol
1 x S = 1 x 32.0 g/mol = 32.0 g/mol
4 x O = 4 x 16.0 g/mol = 64.0 g/mol
Adding up these values, we get:
Molar mass of Na2SO4 = 46.0 g/mol + 32.0 g/mol + 64.0 g/mol = 142.0 g/mol
Now, let's consider the water (H2O) component of the formula. We know that the molar mass of water is 18.0 g/mol, which consists of 2 hydrogen atoms (2 x 1.0 g/mol) and 1 oxygen atom (1 x 16.0 g/mol).
Molar mass of H2O = 2 x 1.0 g/mol + 1 x 16.0 g/mol = 18.0 g/mol
Therefore, the molar mass of Na2SO4 x H2O is given by:
142.0 g/mol + 18.0 g/mol = 160.0 g/mol
Now, let's calculate the number of moles of the hydrated sodium sulphate (Na2SO4 x H2O) in the given sample.
Moles of Na2SO4 x H2O = mass of sample / molar mass
Moles of Na2SO4 x H2O = 1.42 g / 160.0 g/mol = 0.008875 mol
Since we know that the hydrated sodium sulphate (Na2SO4 x H2O) contains x moles of water, we need to calculate the mass of water lost during heating.
Mass of water lost = mass of hydrated sample - mass of anhydrous sample
Mass of water lost = 3.22 g - 1.42 g = 1.80 g
Since the molar mass of water is 18.0 g/mol, we can calculate the moles of water lost during heating:
Moles of water lost = mass of water lost / molar mass of water
Moles of water lost = 1.80 g / 18.0 g/mol = 0.100 mol
From the Law of Conservation of Mass, moles of water lost during heating should be equal to the moles of water in the hydrated sodium sulphate formula:
Moles of water lost = x mol
Therefore, we can equate the two values:
0.100 mol = x mol
Hence, the value of x is 0.100. Therefore, the formula for the hydrated sodium sulphate (Na2SO4 x H2O) is Na2SO4 x 0.1H2O.