Mole Concept & Avogadro's Constant (Deadline: 7th Sep, 6.00 pm))

What is the definition of a mole?

• A mole is the amount of substance in a liter of solution.

• A mole is a measure of temperature in chemistry.

• A mole is a unit of mass equivalent to one gram.

• A mole is 6.022 x 10^23 elementary entities of a substance.

What is the primary use of a mole in chemistry?

• To measure the volume of gases.

• To quantify the amount of substance.

• To determine the temperature of a solution.

• To calculate the density of liquids.

Which of the following best describes Avogadro's number?

• The number of molecules in one liter of gas.

• The number of atoms in one mole of an element.

• The number of particles in one mole of a substance.

• The number of grams in one mole of a substance.

Write the equation to calculate the number of moles.

If 1 mole of rice is 6.02 x 10^23 rice grains, how many rice grains are in 0.5 mole of rice?

• 6.02 x 10^23

• 3.01 x 10^23

• 1.20 x 10^24

• 8.31 x 10^-25

If 1 mole of water has 6.02 x 10^23 water molecules, how many moles are 4.82 x 10^23 water molecules?

• 0.2

• 0.4

• 0.6

• 0.8

If 1 mole of sodium chloride contains 6.02 x 10^23 sodium chloride, NaCl, molecules, how many molecules are there in 0.1 mole of sodium chloride?

• 6.02 x 10^22

• 1.66 x 10^-25

• 1.204 x 10^23

• 3.32 x 10^-25

A chemist measures 0.25 moles of sodium hydroxide, NaOH, how many molecules of sodium hydroxide did the chemist measure?

• 6.02 x 10^23

• 3.01 x 10^23

• 1.505 x 10^23

• 4.15 x 10^-25

If a chemist measures 1.55 x 10^-4 moles of water, how many water molecules did the chemist measure?

• 9.03 x 10^19

• 2.57 x 10^-28

• 3.88 x 10^27

• 3.09 x 10^23