Course Assessment

What is the molar mass of Cl₂?

• 17 g/mol

• 35.5 g/mo;

• 71.0 g/mol

• 89 g/mol

Calculate the molar mass of KOH.

• 28 g/mol

• 56 g/mol

• 84 g/mol

• 112 g/mol

Calculate the molar mass of Cu₂O.

• 37 g/mol

• 45 g/mol

• 79.5 g/mol

• 143 g/mol

How many atoms are present in a 13.5 gram sample of beryllium?

• 1.5 particles

• 9 particles

• 4.03 x10²³ particles

• 9.02 x10²³ particles

A sample of silver contains 5.71 x 10²² atoms. How many moles of silver are present?

• 3.43 x 10⁴⁶ moles

• 0.0529 moles

• 0.0948 moles

• 10.5 moles

How many atoms are present in a 0.0254 mole sample of gold?

• 0.25 atoms

• 1.528 x 10²² atoms

• 4.22 x 10^-25 atoms

• 5 atoms

Which of the following shows the correct setup to determine the number of moles of molecules in a 12.0 gram sample of Cl₂?

• 12/35.5 mole

• 12/71 mole

• 12 moles

• 12 x 35.5 moles

Determine the mass of 2.40 moles of C₆H₁₂

• 201 g

• 115 g

• 230. g

• 353 g

Where are the numbers for a mole ratio found?

• They are part of the chemical formulas for the reactants / products.

• They are given in the problem.

• They are found on the periodic table for those elements.

• They are found as coefficients in the reaction's balanced chemical equation.

2 C₂H₆ + 7 O₂ → 4 CO₂ + 6 H₂O

Ethane (C₂H₆) combusts in the above reaction. What is the mole ratio of ethane to oxygen gas?

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