Chem Review 2/13

What is the percent by mass of oxygen in MgO?

• 20%
• 40%
• 50%
• 60%

Which pair has the same empirical formula?

• NaCrO₄ and Na₂Cr₂O₇
• C₂H₄O₂ and C₆H₁₂O₆
• C₃H₆O₃ and C₂H₆O₂
• CH₄ and C₂H₆

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

• Molecular Formula
• Chemical Formula
• Empirical Formula 
• Distance Formula

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

• K₂SO₄ 
• K₈SO₁₆
• K₈S₄O₈ 
• K₈S₄O₁₆ 

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

What is the mass of 0.2 mol of Al? (Al:27g/mol)

• 27 g

• 54 g

• 5.4 g

• 2.7 g

What is the mass of Na atom that contains 12.04 X 10²³ atoms in its structure? (Na:23g/mol)

• 11.5 g

• 23 g

• 34.5 g

• 46 g

What is the molecular formula if the empirical formula is CH₂O and the molecular molar mass is 180.18?

• CH₂O
• C₂H₄O₂
• C₄H₈O₄
• C₆H₁₂O₆

Tags

NGSS.MS-PS1-1

The chemical formula for an ionic compound of potassium and oxygen is

• KO.
• K₂O.
• K₂O₂.
• KO₂.

Tags

NGSS.MS-PS1-1

The chemical formula for an ionic compound of aluminum and chlorine is

• AlCl.
• ClAl.
• AlCl₃.
• Al₃Cl.

Tags

NGSS.MS-PS1-1