One hundred grams of mixture of NaSO4 – 10H2O and Na2CO3 – 10H2O are heated to drive off water of hydration. The final weight of the mixed salts is 39.6g. What is the ration of moles Na2CO3 to moles Na2SO4 in the original hydrated salts?
39.1gm na2so4,68.9gm na2co3
To find the ratio of moles Na2CO3 to moles Na2SO4 in the original mixture, we need to calculate the number of moles for each compound.
Step 1: Calculate the number of moles of Na2CO3.
The molar mass of Na2CO3 is 22.99 g/mol (2 Na) + 12.01 g/mol (C) + 3(16.00 g/mol) (O) = 105.99 g/mol.
The mass of Na2CO3 in the final mixture is 39.6 g, so the number of moles of Na2CO3 can be calculated using the formula:
moles Na2CO3 = mass Na2CO3 / molar mass Na2CO3
moles Na2CO3 = 39.6 g / 105.99 g/mol
Step 2: Calculate the number of moles of Na2SO4.
The molar mass of Na2SO4 is 22.99 g/mol (2 Na) + 32.07 g/mol (S) + 4(16.00 g/mol) (O) = 142.04 g/mol.
The difference between the initial mixture mass (100 g) and the final weight of the mixed salts (39.6 g) will give us the mass of Na2SO4. So we can calculate the number of moles of Na2SO4:
mass Na2SO4 = initial mass - final mass
mass Na2SO4 = 100 g - 39.6 g
moles Na2SO4 = mass Na2SO4 / molar mass Na2SO4
moles Na2SO4 = (100 g - 39.6 g) / 142.04 g/mol
Step 3: Calculate the ratio of moles Na2CO3 to moles Na2SO4.
moles Na2CO3 / moles Na2SO4 = (39.6 g / 105.99 g/mol) / ((100 g - 39.6 g) / 142.04 g/mol)
Simplifying the expression, we get:
moles Na2CO3 / moles Na2SO4 = (0.373 mol) / (0.475 mol)
Thus, the ratio of moles Na2CO3 to moles Na2SO4 in the original hydrated salts is approximately 0.78 (rounded to two decimal places).
To find the ratio of moles of Na2CO3 to moles of Na2SO4 in the original hydrated salts, we need to first determine the amount of each salt in the mixture based on their final weight after heating.
Let's start by calculating the individual masses of Na2CO3 and Na2SO4 in the 100g mixture.
Given:
Total weight of the mixture = 100g
Final weight of the mixed salts = 39.6g
Mass of Na2CO3 + Na2SO4 = Final weight of the mixed salts
Mass of Na2CO3 + Mass of Na2SO4 = 39.6g
Now, let's represent the moles of Na2CO3 and Na2SO4:
Moles of Na2CO3 = n(Na2CO3)
Moles of Na2SO4 = n(Na2SO4)
To compare the moles of Na2CO3 and Na2SO4, we can use their molar masses.
The molar mass of Na2CO3 = 2*22.99 (Na) + 12.01(C) + 3*16.00(O) = 105.99 g/mol
The molar mass of Na2SO4 = 2*22.99 (Na) + 32.07(S) + 4*16.00(O) = 142.04 g/mol
Therefore, the moles of Na2CO3 can be calculated as:
n(Na2CO3) = Mass of Na2CO3 / Molar mass of Na2CO3
Similarly, the moles of Na2SO4 can be calculated as:
n(Na2SO4) = Mass of Na2SO4 / Molar mass of Na2SO4
Since we do not have the individual masses of Na2CO3 and Na2SO4, we need additional information to solve the problem. Specifically, we need to know the percentage composition of Na2CO3 and Na2SO4 in the mixture before heating.
Once we have the individual masses of Na2CO3 and Na2SO4, we can calculate their moles and find the ratio of moles Na2CO3 : moles Na2SO4.