A 32.907-g sample of a hydrate of Au (CN)3 contains 5.406 g H2O
What is the formula for the hydrate?
What is the percent water in this compound?
What mass of this hydrate contains 100.0 g H2O?
mass Au(CN)3 + H2O = 32.907g
mass H2O = 5.406g
mass Au(CN)3 = 32.907-5.406 = ?g
Convert ?g Au(CN)3 to mols = ?
Convert 5.406g H2O to mols ?
Find the ratio of mols H2O to 1 mol Au(CN)3 to find the formula.
%H2O = (mass H2O/total mass)*100 = ?
For part c, use the percent formula you just finished, substitute the numbers you want and solve for total mass.
wasting out time drbob
To determine the formula for the hydrate, we need to calculate the molar ratio between the hydrate and the water.
Step 1: Calculate the number of moles of Au(CN)3 and H2O.
Molar mass of Au(CN)3 = 1 * 196.97 (molar mass of Au) + 3 * 12.01 (molar mass of C) + 3 * 14.01 (molar mass of N) = 303.03 g/mol
Molar mass of H2O = 2 * 1.01 (molar mass of H) + 16.00 (molar mass of O) = 18.02 g/mol
Moles of Au(CN)3 = mass / molar mass = 32.907 g / 303.03 g/mol = 0.1083 mol
Moles of H2O = mass / molar mass = 5.406 g / 18.02 g/mol = 0.2997 mol
Step 2: Determine the mole ratio between Au(CN)3 and H2O.
Divide the number of moles of H2O by the number of moles of Au(CN)3 to find the mole ratio.
Mole ratio = Moles of H2O / Moles of Au(CN)3 = 0.2997 mol / 0.1083 mol ≈ 2.76
Step 3: Write the formula for the hydrate.
The formula for the hydrate is determined by the mole ratio mentioned above.
Therefore, the formula for the hydrate is Au(CN)3·2.76H2O.
To calculate the percent water in this compound, we divide the mass of water by the total mass of the hydrate and multiply by 100.
Percent water = (mass of water / total mass of hydrate) * 100 = (5.406 g / 32.907 g) * 100 ≈ 16.44%
Finally, to determine the mass of this hydrate that contains 100.0 g H2O, we use the mole ratio calculated earlier.
Mass of hydrate = mass of water / mole ratio = 100.0 g / 2.76 ≈ 36.23 g.
Therefore, 36.23 g of this hydrate contains 100.0 g H2O.
To determine the formula for the hydrate, we need to calculate the molar ratio between Au (CN)3 and H2O. We can do this by calculating the moles of Au (CN)3 and H2O and then simplifying the ratio.
Step 1: Calculate the moles of Au (CN)3
First, we need to determine the molar mass of Au (CN)3. Gold (Au) has a molar mass of 196.97 g/mol, and cyanide (CN) has a molar mass of 26.02 g/mol. Since there are three cyanide molecules in Au (CN)3, we need to multiply the molar mass of CN by 3.
Molar mass of Au (CN)3 = (196.97 g/mol) + 3 * (26.02 g/mol)
= 196.97 g/mol + 78.06 g/mol
= 275.03 g/mol
Next, we can calculate the moles of Au (CN)3 using the mass given:
Moles of Au (CN)3 = Mass of Au (CN)3 / Molar mass of Au (CN)3
= 32.907 g / 275.03 g/mol
= 0.11978 mol
Step 2: Calculate the moles of H2O
Now, we need to determine the moles of water (H2O) using the mass given:
Moles of H2O = Mass of H2O / Molar mass of H2O
= 5.406 g / 18.015 g/mol
= 0.29973 mol
Step 3: Simplify the ratio
Finally, we can simplify the molar ratio between Au (CN)3 and H2O:
Molar ratio = Moles of Au (CN)3 / Moles of H2O
= 0.11978 mol / 0.29973 mol
= 0.3998
Since this ratio is approximately 0.4, we can say that the formula for the hydrate is Au (CN)3 · 0.4H2O.
To determine the percent water in this compound, we need to calculate the mass of water as a percentage of the total mass.
Percent water = (Mass of H2O / Total mass) * 100%
= (5.406 g / 32.907 g) * 100%
= 16.42%
So, the compound is approximately 16.42% water.
To calculate the mass of this hydrate that contains 100.0 g H2O, we can use the proportionality between the mass of water and the total mass of the hydrate.
Mass of hydrate = (Mass of H2O / Percent water) * 100%
= (100.0 g / 16.42%) * 100%
= 608.22 g
Therefore, 608.22 grams of this hydrate contain 100.0 g of H2O.