Moles, Percent Composition, Empirical and Molecular Formulas

A formula with the lowest whole # ratio of elements in a compound is called

• Molecular Formula

• Chemical Formula

• Empirical Formula 

• Distance Formula

A chemical formula that shows the actual # and kinds of atoms present in one molecule of a compound is called_________

• ionic formula

• covalent formula

• empirical formula

• molecular formula

Find the percent composition of Cu₂S?

• %Cu= 67.987 %S= 32.013

• %Cu= 79.854   %S= 20.145

• %Cu= 35.946   %S= 64.054

How many molecules are in 2.5 mol of NaCl?

• 51x10²³

• 146

• 4.15

• 1.51x10²⁴

What is the molar mass of table salt (NaCl)?

• 116.886 g/mol

• 35.453 g/mol

• 22.990 g/mol

• 58.443 g/mol

Tags

NGSS.HS-PS1-7

Given the following: 42.07% Na, 18.89% P, and 39.04% O, determine the empirical formula.

•  NaPO2

• Na2PO3

• Na3PO4

• NaPO4

What is the percent by mass of oxygen in MgO?

• 20%

• 40%

• 50%

• 60%

Tags

NGSS.HS-PS1-7

You are given the following percentages: 40.05% S and 59.95% O. Find the empirical formula for these elements.

• SO

• SO2

• SO3

• SO4

What is the molecular formula for a compound with the empirical formula: K₂SO₄ and a molecular mass of 696g.

• K₂SO₄ 

• K₈SO₁₆

• K₈S₄O₈ 

• K₈S₄O₁₆ 

An empirical formula:

• is a formula that calculates the coefficients of a compound in a balanced equation.

• is the simplest whole-number ratio of moles of elements in the compound.