Molar Mass - Mass to Grams to Atoms

Samar is working on a chemistry project and needs to calculate the mass of one mole of sodium chloride. Which of the following refers to the mass of one mole of substance?

• molecular mass

• mole constant

• molar mass

• atomic weight

Answer explanation

The correct choice is 'molar mass' which refers to the mass of one mole of a substance in chemistry.

Ethan is working on a chemistry project and needs to calculate the amount of sodium required. He wonders, what is the molar mass of sodium?

• 11 amu

• 23 g/mol

• 23 amu

• 11 g/mol

Answer explanation

The molar mass of sodium is 23 g/mol. This is the correct choice as it represents the mass of one mole of sodium atoms.

Elijah is working on a chemistry project and needs to know the mass of one mole of aluminum for his experiment. What is the mass?

• 27 g/mol

• 27 amu

• 13 g/mol

• 13 amu

Answer explanation

The correct mass of one mole of aluminum is 27 g/mol. This is the molar mass of aluminum, which is the mass of one mole of aluminum atoms.

What is the molar mass of table salt (NaCl)?

• 116.886 g/mol

• 35.453 g/mol

• 22.990 g/mol

• 58.443 g/mol

Answer explanation

The molar mass of table salt (NaCl) is calculated by adding the atomic masses of sodium (Na) and chlorine (Cl), which are 22.990 g/mol and 35.453 g/mol respectively. Therefore, the molar mass of NaCl is 22.990 g/mol + 35.453 g/mol = 58.443 g/mol.

What is the molar mass of NaOH?

• 40 g/mol

• 38.989 g/mol

• 23.998 g/mol

• 57.004 g/mol

Answer explanation

The molar mass of NaOH is calculated by adding the atomic masses of Na (22.989) + O (16.00) + H (1.008), which equals 40 g/mol. Therefore, the correct answer is 40 g/mol.

Abigail is conducting a science experiment in her lab to calculate the emissions from a car's exhaust. She needs to know the molar mass of CO₂ for her calculations. What is the molar mass of CO₂?

• 12 g/mol

• 16 g/mol

• 32 g/mol

• 44 g/mol

Answer explanation

The molar mass of CO2 is calculated by adding the atomic masses of carbon (12 g/mol) and two oxygen atoms (16 g/mol each), resulting in a total of 44 g/mol.

How many particles are in a mole?

• 602

• 602 million

• 602 moles

• 6.02 x 10²³

Answer explanation

A mole contains 6.02 x 10^23 particles, known as Avogadro's number.

During a science project, Ansh and Ishaan are calculating the molar mass of chlorine gas (Cl₂) for their experiment. What is the molar mass they should use?

• 17 g/mol

• 35.5 g/mo

• 71.0 g/mol

• 89 g/mol

Answer explanation

The molar mass of Cl2 is calculated by adding the atomic masses of two chlorine atoms, which is 35.5 g/mol each. Therefore, the molar mass of Cl2 is 71.0 g/mol.

During a science project, Nick is calculating the molar mass of UF₆ to understand its properties for a presentation. What is the molar mass of UF₆?

• 101 g/mol

• 238 g/mol

• 257 g/mol

• 352 g/mol

Answer explanation

The molar mass of UF6 is 352 g/mol because the atomic mass of uranium (U) is 238 g/mol and the atomic mass of fluorine (F) is 19 g/mol, multiplied by 6 fluorine atoms.

Calculate the molar mass of KOH.

• 28 g/mol

• 56 g/mol

• 84 g/mol

• 112 g/mol

Answer explanation

The molar mass of KOH is calculated by adding the atomic masses of each element: K (39.10 g/mol) + O (16.00 g/mol) + H (1.01 g/mol) = 56 g/mol.