Atoms and the Mole

Which of the following statements regarding the mole is INCORRECT?

• A mole is a unit of quantity equal to 6.02 x 10²³ particles.

• The number of particles in a mole is known as Avogadro’s number.

• A mole of particles of an element is numerically equal to the atomic mass of the element.

• none of the above

The mass of one mole of an element is equal to

• its atomic number from the periodic table, but in amus.

• its atomic mass from the periodic table, but in amus.

• its atomic mass from the periodic table, but in grams.

• its atomic number from the periodic table, but in grams.

What is the molar mass of PbSO₄?

• 303.27 g/mol

• 255.27 g/mol

• 163.87 g/mol

• 372.27 g/mol

How many formula units are in 2.5 moles of NaCl?

• 1.5 x10²⁴ formula units

• 1.5 formula units

• 4.2 formula units

• 4.2 x10^-24 molecules

How many molecules are there in 31.8 moles of water?

• 5.28 x 10^-23 molecules
• 1.91 x 10²⁵ molecules
• 5.28x 10-²⁵
• 1.91 x 10²²

Determine the mass of 4.20 moles of C₆H₁₂

• 353 g

• 0.0499 g

• 337 g

• 2.53 x 10²⁴ g

Which of the following dimensional analysis setups will correctly convert 27.76 g of Li to atoms of Li?

• A

• B

• C

• D

What is the mass of 1.2 x 10²⁴ atoms of C?

• 2.0 grams

• 24 grams

• 0.17 grams

• 1.4 x 10²⁵ grams

Which of the following dimensional analysis setups will correctly convert 4.00x10²³atoms of cobalt to moles of cobalt? How many moles of colbalt are there?

• setup B : 0.664 mol Co

• setup A: 2.41x10⁴⁷mol Co

• setup A : 0.664 mol Co

• setup B: 2.41x10⁴⁷mol Co

Protons and neutrons are found in the center of the atom called the:

• nucleus

• neutron

• shell

• cell