Calculating Mass in Reactions

• What is the measurement of volume equal to 1,000 centimeters cubed?

  One decimeter cubed
• What is the equation for concentration?

  Mass divided by volume
• How do you represent concentration in grams per decimeter cubed?

  As grams per $dm^{-3}$
• What does the horizontal line in a formula triangle represent?

  • It means divide
  • The vertical line means multiply
• If you want to find the concentration using the formula triangle, what do you cover up?

  Cover up the 'c'
• How do you calculate the concentration of sodium hydroxide in 40 grams dissolved in 2.5 decimeters cubed?

  40 grams divided by 2.5 decimeters cubed
• How can we express 'per decimeters cubed' in a shorter form?

  As $dm^{-3}$
• How do you convert 480 centimeters cubed to decimeters cubed?

  Divide by 1000
• What is the concentration of copper sulfate in 24 grams dissolved in 480 centimeters cubed?

  50 grams per decimeter cubed
• Why is it important to check the units of the figures given in a problem?

  To avoid common mistakes in calculations
• How do you calculate mass if given concentration and volume?

  Mass equals concentration times volume
• What is the concentration of hydrochloric acid in a 400 centimeters cubed sample with 20 grams per decimeter cubed?

  8 grams
• How do you convert 400 centimeters cubed to decimeters cubed?

  Divide by 1000
• What is the final mass of hydrogen chloride in the solution?

  8 grams
• What are the steps to calculate concentration from mass and volume?

  1. Identify mass in grams
  2. Identify volume in decimeters cubed
  3. Use the formula: concentration = mass / volume
  4. Ensure units are consistent
• What are common pitfalls in concentration calculations?

  • Confusing grams with kilograms
  • Mixing centimeters cubed with decimeters cubed
  • Not converting units properly