Chemistry: Temperature, Calorie, and Scientific Notation

Key Concepts of Significant Figures and Calorimetry

• Significant Figures
  • Determines the precision of a number.
  • Example: 90 has only one significant figure, limiting accuracy.
• Multiplication & Division in Significant Figures
  • In calculations, the result should not have more significant figures than the measurement with the least significant figures.

Caloric Definition

• Calorie
  • Defined as the amount of heat energy required to raise the temperature of 1 gram of water by 1 degree Celsius.
  • Water serves as a universal standard in scientific experiments.

Types of Caloric Changes

• Two Types of Energies
  • Heat energy can result from heating (calorimetry) or cooling substances.
  • Understanding these forms is crucial depending on the context of the problem.

Problem Example: Time Calculation

• To calculate the time to travel two distances:
  • Use constant velocity.
  • Example Calculation: How much time it takes to travel 391.4 miles.

Handling Significant Figures in Calculations

• Use scientific notation for numbers that require two significant figures.
  • Example: $8.00 = 8.0 \times 10^0$; indicates precision in significant figures.
• Keep in mind that initial and final values must be carefully selected when conducting calculations in calorimetry.