Understanding Moles and Chemical Calculations

What is the significance of Avogadro's constant in chemistry?

• It is used to calculate the speed of light.

• It determines the boiling point of water.

• It represents the number of particles in one mole of a substance.

• It measures the volume of a gas.

How many moles are present in 42.5 g of ammonia if its molar mass is 17 g/mol?

• 4.5 moles

• 3.5 moles

• 2.5 moles

• 1.5 moles

If you have 3 moles of carbon dioxide, what is the total mass of carbon in it?

• 24 g

• 12 g

• 48 g

• 36 g

In a chemical reaction, if one mole of magnesium reacts with two moles of hydrochloric acid, what is produced?

• Two moles of magnesium chloride and hydrogen gas

• Three moles of magnesium chloride and hydrogen gas

• One mole of magnesium chloride and hydrogen gas

• No reaction occurs

What does the ratio in a chemical equation represent?

• The proportion of moles of reactants and products

• The speed of the reaction

• The temperature at which the reaction occurs

• The color change during the reaction