Mole Concept

What is the mass of 6.02 x 10²³ platinum atoms? Round to the nearest hundredths place.

• 30.97 g

• 106.42 g

• 140.91 g

• 195.09 g

A student needs 65.0 g of copper(II) chloride for an experiment. How many atoms of copper is this?

• 2.91 x 10^23 atoms

• 3.91 x 10^25 atoms

• 2.35 x 10^23 atoms

• 4.70 x 10^23 atoms

Tags

NGSS.HS-PS1-7

The molecular formula for a carbon and hydrogen compound is C₈H₁₈. What is the empirical formula?

• C₈H₁₈

• C₉H₄

• C₁₈H₈

• C₄H₉

If one Monster energy drink contains 0.16 g of caffeine, how many moles of caffeine do we consume when we drink 1 can? The chemical formula for caffeine is C₈H₁₀N₄O₂.

• 194.19 moles

• 1.07 moles

• 0.00082 moles

• 1213.69 moles

Tags

NGSS.HS-PS1-7

Which of the following statements regarding the mole is incorrect?

• A mole is a counting unit 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

Mylanta, a common antacid, contains magnesium hydroxide, Mg(OH)₂. How many moles of magnesium hydroxide are in 75.0 g of magnesium hydroxide?

• 0.551 moles

• 0.778 moles

• 1.29 moles

• 1.82 moles

Tags

NGSS.HS-PS1-7

Which of the following compounds is correctly matched with its empirical formula?

• Dihydrogen dioxide - H₂O₂

• Hydrogen dioxide - H2O

• Tetrahydrogen dioxide - H4O2

• Dihydrogen dioxide - HO

Tags

NGSS.MS-PS1-1

Acetone, C₃H₆O, is the main component of fingernail polish remover. What is the molar mass of acetone to the nearest hundredths place?

• 29.018 g/mol

• 34.058 g/mol

• 58.1 g/mol

• 58.08 g/mol

What is the percent composition of hydrogen in water?

• 89.8%

• 11.2%

• 66.7%

• 33.3%

An empirical formula is defined as _______?

• The lowest whole number ratio of atoms in a formula.

• The actual whole number ratio of atoms in a formula.

• The formula showing the ratio of atoms in a formula.

• The formula showing the ratio of moles in a formula.