A sample of calcium chloride weighs 1.64g it is dissolved in water and sliver trioxonitrate(v)solution added. A precipitate of Agcl weighing 4.24g was formed .Determine the % composition and the simplest formula of calcium chloride.
I have rounded to th nearest 0.1 for these calculations. By the way, a correct IUPAC name for AgNO3 is silver nitrate. The name you used is not an accepted name for AgNO3.
mass AgCl = 4.24 g. Convert to mass Cl in the sample.
4.24 g AgCl x (atomic mass Cl/molar mass CaCl2) = 4.24 x (35.45/143.32) = 1.048 g Cl.
% Cl = (mass Cl/mass sample) = (1.049/1.64)*100 = 64.0%
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empirical formula
% Cl = 64
% Ca = 100 - 64 = 36
Take a 100 g sample giving you 36 Ca and 64 g Cl
mols Ca = 36/40 = 0.9
mols Cl = 64/35.5 = 1.8 and ratios are
Ca = 0.9/0.9 = 1.0
Cl = 1.8/0.9 = 2.0
empirical formula is ??
To determine the % composition and simplest formula of calcium chloride, we need to use the given information.
First, let's calculate the amount of chloride ions present in the AgCl precipitate.
1. Calculate the molar mass of AgCl:
Ag (silver) has a molar mass of 107.87 g/mol
Cl (chlorine) has a molar mass of 35.45 g/mol
Molar mass of AgCl = 107.87 g/mol + 35.45 g/mol = 143.32 g/mol
2. Calculate the number of moles of AgCl:
Moles of AgCl = mass of AgCl / molar mass of AgCl
Moles of AgCl = 4.24 g / 143.32 g/mol ≈ 0.0296 mol
3. Because 1 mol of AgCl contains 1 mol of Cl ions, the molar ratio between Cl ions and AgCl is 1:1.
4. Calculate the number of moles of Cl ions:
Moles of Cl ions = 0.0296 mol
Next, let's determine the amount of calcium chloride in the sample.
5. Calculate the molar mass of calcium chloride (CaCl2):
Ca (calcium) has a molar mass of 40.08 g/mol
Cl (chlorine) has a molar mass of 35.45 g/mol
Molar mass of CaCl2 = 40.08 g/mol + (2 × 35.45 g/mol) = 110.98 g/mol
6. Calculate the number of moles of calcium chloride:
Moles of CaCl2 = mass of CaCl2 / molar mass of CaCl2
Moles of CaCl2 = 1.64 g / 110.98 g/mol ≈ 0.0148 mol
Finally, let's calculate the % composition and simplest formula of calcium chloride.
7. Calculate the % composition of chloride in calcium chloride:
% Composition of chloride = (moles of Cl ions / moles of CaCl2) × 100
% Composition of chloride = (0.0296 mol / 0.0148 mol) × 100 ≈ 200%
Since the % composition of chloride is greater than 100%, it is clear that the formula of calcium chloride is incorrect as CaCl2. We need to adjust the ratio of Ca to Cl to obtain a valid formula.
8. Determine the simplest formula of calcium chloride:
To find the simplest formula, we need to divide the number of moles of each element by the smallest number of moles.
Dividing the number of moles of Cl ions by the smallest number of moles (0.0148 mol) gives:
Moles of Cl ions / 0.0148 mol ≈ 1.99
Since we cannot have a fraction in a formula, we will round it to the nearest whole number:
Moles of Cl ions = 2
Moles of Ca = 0.0148 mol
The simplest formula for calcium chloride is CaCl2.
Therefore, the % composition of chloride in calcium chloride is approximately 200%, and the simplest formula for calcium chloride is CaCl2.
To determine the percent composition and simplest formula of calcium chloride, we need to analyze the information given and apply some basic stoichiometry.
Let's start by writing a balanced chemical equation for the reaction that occurs between calcium chloride (CaCl2) and silver trioxonitrate(V) (AgNO3), which forms a precipitate of silver chloride (AgCl):
2AgNO3 + CaCl2 -> 2AgCl + Ca(NO3)2
According to the equation, 1 mole of CaCl2 reacts with 2 moles of AgNO3 to form 2 moles of AgCl. We can use this information to calculate the moles of CaCl2 in the sample.
The molar mass of AgCl is the sum of the atomic masses of silver (Ag) and chlorine (Cl), which can be found in the periodic table.
Ag: 107.87 g/mol
Cl: 35.45 g/mol
AgCl: 107.87 g/mol + 35.45 g/mol = 143.32 g/mol
Now, let's calculate the moles of AgCl formed:
moles of AgCl = mass of AgCl / molar mass of AgCl
moles of AgCl = 4.24 g / 143.32 g/mol = 0.0296 mol
Since 2 moles of AgCl are formed from 1 mole of CaCl2, we can assume that the moles of CaCl2 in the sample are half of the moles of AgCl:
moles of CaCl2 = 0.0296 mol / 2 = 0.0148 mol
Now, let's calculate the mass of CaCl2 in the sample:
mass of CaCl2 = moles of CaCl2 × molar mass of CaCl2
mass of CaCl2 = 0.0148 mol × (40.08 g/mol + 2 × 35.45 g/mol) = 1.76 g
To determine the percent composition of calcium chloride (% comp), divide the mass of Ca by the total mass of the compound and multiply by 100:
% comp of Ca = mass of Ca / mass of CaCl2 × 100
% comp of Ca = (40.08 g/mol / (40.08 g/mol + 2 × 35.45 g/mol)) × 100 = 25.43%
Similarly, the percent composition of chlorine (% comp) can be calculated as:
% comp of Cl = mass of Cl / mass of CaCl2 × 100
% comp of Cl = (2 × 35.45 g/mol / (40.08 g/mol + 2 × 35.45 g/mol)) × 100 = 74.57%
Therefore, the percent composition of calcium chloride is approximately 25.43% calcium (Ca) and 74.57% chlorine (Cl).
To determine the simplest formula of calcium chloride, we need to find the ratio of the elements. Since the mole ratio between calcium and chloride is 1:2, the simplest formula of calcium chloride is CaCl2.
In summary, the percent composition of the sample of calcium chloride is approximately 25.43% calcium (Ca) and 74.57% chlorine (Cl), and the simplest formula of calcium chloride is CaCl2.