A sample of ammonium salt (NH4X) having a mass of 1.618g was heated with NaOH and the liberated ammonia was reacted with 50.00 of .6230 mol/L HCl. The excess acid required 1.50 mL of .6115 mol/L NaOH in titration. What is the formula of the salt?
mols HCl used = 0.05000 x 0.6230 = ?
back titrated with NaOH = 0.0015 x 0.6115 = ?
mols NH3 present = total mols HCl-mols NaOH in back titration.
Then mol = grams/molar mass.
You know mols and grams, solve for molar mass. Subtract total molar mass - N - 4*H to find atomic mass of X then compare wth periodic table to identify X. I think it's Cl.
To determine the formula of the salt, we can use stoichiometry and the concept of chemical reactions. Here are the steps you can follow to find the formula of the salt:
Step 1: Calculate the moles of HCl used in the titration.
The volume of the HCl used is given as 50.00 mL, and the concentration is given as 0.6230 mol/L. We can use the formula: moles = (concentration * volume) / 1000
Calculating it:
moles of HCl = (0.6230 mol/L * 50.00 mL) / 1000
moles of HCl = 0.0312 mol
Step 2: Calculate the moles of NaOH used in the titration.
The volume of NaOH used in excess is given as 1.50 mL, and the concentration is given as 0.6115 mol/L.
Calculating it:
moles of NaOH = (0.6115 mol/L * 1.50 mL) / 1000
moles of NaOH = 0.000917 mol
Step 3: Determine the moles of NH3 produced in the reaction between NH4X and NaOH.
Since 1 mole of NH4X reacts with 1 mole of NaOH to produce 1 mole of NH3, the moles of NH3 produced would be the same as the moles of NaOH.
moles of NH3 = 0.000917 mol
Step 4: Calculate the moles of NH4X in the given sample.
To find the moles of NH4X, we need to find the ratio of NH3 to NH4X.
The molar ratio can be determined by multiplying the coefficient before NH3 (1) with the reciprocal of the coefficient (if any) before NH4X (let's say 'x').
1 * (1/x) = 1/x
Since the moles of NH3 and NH4X are the same:
moles of NH3 = moles of NH4X = 0.000917 mol
Step 5: Determine the molar mass of the salt (NH4X).
To calculate the molar mass, we need the mass of the sample. It is given as 1.618 g.
molar mass of NH4X = mass / moles
molar mass of NH4X = 1.618 g / 0.000917 mol
Step 6: Determine the empirical formula.
To find the empirical formula, we need to divide each subscript in the formula (NH4X) by its corresponding molar mass.
empirical formula = NH4X / molar mass of NH4X
Now, you can perform the calculations to determine the empirical formula of the salt using the given data.