Question

sweredThe chloride of an unknown metal is believed to have the formulaMCI3. A 1.95-g sample of the compound is found to contain0.03606 mol CI. Calculate the atomic mass of M. Enter youranswer as a number to 1 decimal place.t Answersmass=_ g/molBetween 55.7 and 56.1

Answer 1

Answer

55.9 g/mol

Explanation

Given:

The mass of the sample = 1.95 g

Moles of Cl in the sample = 0.03606 mol

What to find:

To determine the atomic mass of M.

Step-by-step solution:

Step 1: Determine the mass of Cl in the sample.

Since it was given that 0.03606 mol of Cl is found in the sample, then the mass of Cl in the 1.95 g of the sample will be:

$\begin{gathered} Mass=Moles\times Molar\text{ }mass \\ \\ Molar\text{ }mass\text{ }of\text{ }Cl=35.453\text{ }g\text{/}mol \\ \\ Mass\text{ }of\text{ }Cl=0.03606\text{ }mol\times35.453\text{ }g\text{/}mol \\ \\ Mass\text{ }of\text{ }Cl=1.27844\text{ }mol \end{gathered}$

Step 2: Determine the mass of metal M in the compound.

Mass of metal M = Mass of MCl₃ sample - Mass of Cl

Mass of metal M = 1.95 g - 1.27844 g

Mass of metal M = 0.67156 g

Step 3: Determine the mole of M.

From the formula of the compound, (MCl₃), the M to Cl molar ratio is 1 to 3. Therefore, moles M in the sample:

$Moles\text{ }of\text{ }M=\frac{0.03606\text{ }mol}{3}=0.01202\text{ }mol$

Step 3: Calculate the atomic mass of M.

The atomic mass of M can be calculated using the mass of M in step 2 and and the moles of M in step 3 above:

$Atomic\text{ }mass=\frac{Mass\text{ }of\text{ }M}{Moles\text{ }of\text{ }M}=\frac{0.67156\text{ }g}{0.01202\text{ }mol}=55.9\text{ }g\text{/}mol$

Hence, the atomic mass of M is 55.9 g/mol