Question

calculate the percent composition by mass of yttrium in the fictional compound shown below. include the units, but do not write the chemical formula. round the answer to 3 significant figures. y₆mn₂cl₅ yttrium =

Explanation:

Step1: Find molar masses

Molar mass of Y (Yttrium) = 88.91 g/mol, Mn = 54.94 g/mol, Cl = 35.45 g/mol.

Step2: Calculate total mass of Y

For \( Y_6 \): \( 6 \times 88.91 = 533.46 \) g/mol.

Step3: Calculate total mass of compound

Mass of \( Mn_2 \): \( 2 \times 54.94 = 109.88 \) g/mol.
Mass of \( Cl_5 \): \( 5 \times 35.45 = 177.25 \) g/mol.
Total mass = \( 533.46 + 109.88 + 177.25 = 820.59 \) g/mol.

Step4: Calculate percent composition

Percent Y = \( \frac{533.46}{820.59} \times 100 \approx 65.0\% \) (rounded to 3 significant figures).

Answer:

65.0%