Fall 24 5th Block Chapter 7 Test

The molar mass of an element is the mass of one

• atom of the element.
• gram of the element.
• crystal of the element.
• mole of the element.

What is the percentage composition of CF₄ ?

• 20% C, 80% F
• 13.6% C, 86.4% F
• 16.8% C, 83.2% F
• 81% C, 19% F

What is the molar mass of magnesium chloride, MgCl₂ ?

• 46 g/mol
• 95.21 g/mol
• 59.76 g/mol
• 106.35 g/mol

The molar mass of MgBr₂ is

• the sum of the masses of 1 mol of Mg and 2 mol of Br
• the sum of the masses of 1 mol of Mg and 1 mol of Br
• the sum of the masses of 1 atom of Mg and 2 atoms of Br
• the sum of the masses of 1 atom of Mg and 1 atom of Br

What is the percentage composition of CO?

• 50% C, 50% O
• 12% C, 88% O
• 25% C, 75% O
• 43% C, 57% O

A formula that shows the simplest whole-number ratio of the atoms in a compound is the

• Molecular formula.
• Ideal formula.
• Experimental formula.
• Empirical formula.

The empirical formula for a compound shows the symbols of the elements with subscripts indicating the

• Actual numbers of atoms in a molecule.
• Number of moles of the compound in 100 g.
• Smallest whole-number ratio of the atoms.
• Atomic masses of each element.

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

• ionic formula.
• empirical formula.
• covalent formula.
• molecular formula.

A compound’s empirical formula is N₂O₅, what is the molecular formula?

• N₂O₆
• NO₃
• N₄O₁₀
• N₂O₄

What is the name of the following compound: LiNO₃?

• lithium nitride
• lithium nitrate
• impossible to name
• lithium nitrite