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In an experiment, 2.0 moles of oxygen atoms reacts with 80.1 g of calcium to form a new compound. What is the percent composition by mass of each element in the new compound?

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Step-by-step explanation:

The balanced equation for the reaction is:

2 O + Ca → Compound

From the information given, we know that 2.0 moles of oxygen atoms reacts with 80.1 g of calcium. To find the percent composition by mass of each element in the new compound, we first need to determine the molar mass of the compound.

The molar mass of the compound can be calculated by adding up the molar masses of oxygen and calcium.

Molar mass of O = 2 x (16.00 g/mol) = 32.00 g/mol

Molar mass of Ca = 40.08 g/mol

Molar mass of Compound = 32.00 g/mol + 40.08 g/mol = 72.08 g/mol

Now we can use this information to find the percent composition by mass of each element in the compound.

% mass of O = (moles of O x molar mass of O) / molar mass of Compound x 100

% mass of O = (2.0 moles x 32.00 g/mol) / 72.08 g/mol x 100 = 44.68%

% mass of Ca = (moles of Ca x molar mass of Ca) / molar mass of Compound x 100

% mass of Ca = (80.1 g / 40.08 g/mol) / 72.08 g/mol x 100 = 55.32%

So, the percent composition by mass of oxygen in the new compound is 44.68% and the percent composition by mass of calcium in the new compound is 55.32%

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