Moles

• What does the term mole refer to in chemistry?

  A unit to measure the amount of substance
• How many particles are in one mole of a substance?

  $6.02 \times 10^{23}$ particles
• What does Avogadro's constant represent?

  The number of particles in one mole
• What is the weight of one mole of carbon?

  12 grams
• How much does one mole of oxygen weigh?

  32 grams
• What is the weight of one mole of CO2?

  44 grams
• What is the formula to calculate the number of moles?

  Number of moles = mass / relative formula mass
• How many moles are in 42.5 grams of ammonia?

  2.5 moles
• What is the relative formula mass (Mr) of ammonia?

  17
• What is the mass of 3 moles of carbon dioxide?

  132 grams
• How do you calculate the mass of carbon in 3 moles of CO2?

  Multiply 3 moles by 12 grams
• What is the mass of carbon in 3 moles of CO2?

  36 grams
• What is the mass of oxygen in 3 moles of CO2?

  96 grams
• How can chemical equations be interpreted in terms of moles?

  As ratios of reactants and products
• How many moles of hydrochloric acid react with 2 moles of magnesium?

  4 moles
• What is produced when 2 moles of magnesium react?

  2 moles of magnesium chloride
• What gas is produced when magnesium reacts with hydrochloric acid?

  Hydrogen gas
• What is the relationship between moles and chemical reactions?

  Moles represent the ratio of substances
• What does the equation link in chemistry?

  Number of moles, concentration, and volume
• How is volume measured in this context?

  In decimeters cubed
• How is concentration expressed in this context?

  Moles per decimeter cubed
• What does the forward slash in concentration signify?

  It means per unit volume
• What do the letters n, c, and v represent in the formula?

  n for moles, c for concentration, v for volume
• How do you convert 800 centimeters cubed to decimeters cubed?

  Divide by 1000 to get 0.8
• What is the total number of moles in 800 cm³ of sodium hydroxide at 0.2 moles/dm³?

  0.16 moles
• How do you find the concentration of hydrochloric acid given 0.6 moles in 1.5 dm³?

  Divide moles by volume
• What is the concentration of hydrochloric acid in this scenario?

  0.4 moles per decimeter cubed
• What is the first step in solving for an unknown concentration or volume?

  Identify known values from the question
• How do you convert 30 cm³ to decimeters cubed?

  Divide by 1000 to get 0.03
• How do you convert 25 cm³ to decimeters cubed?

  Divide by 1000 to get 0.025
• What is the basic idea behind these types of chemistry questions?

  Calculate moles, use molar ratio, find concentration
• How do you calculate moles of potassium hydroxide?

  Multiply concentration by volume
• What is the number of moles of potassium hydroxide in this scenario?

  0.015 moles
• How do you determine the molar ratio between potassium hydroxide and sulfuric acid?

  By looking at coefficients in the equation
• What is the molar ratio of potassium hydroxide to sulfuric acid in this case?

  2 to 1
• How do you find moles of sulfuric acid from potassium hydroxide moles?

  Divide potassium hydroxide moles by 2
• What is the number of moles of sulfuric acid reacted?

  0.0075 moles
• How do you calculate the concentration of sulfuric acid?

  Divide moles by volume
• What is the concentration of sulfuric acid in this scenario?

  0.3 moles per decimeter cubed
• What are the steps to find an unknown concentration or volume in a chemical reaction?

  1. Identify known values from the question
  2. Convert all volumes to decimeters cubed
  3. Calculate moles of known substance
  4. Use molar ratio to find moles of unknown
  5. Calculate concentration of unknown substance