Chapter 1 - Matter and Measurements PDF

# Matter and Measurements - **T(°F) = 1.8 T(°C) + 32°** - **T(K) = T(°C) + 273.15** **Example**: The temperature of a system is measured to be 75.4°F. An equivalent temperature would be: - **K - 273 = (F - 32) / 1.8** - **(75.4 - 32) / 1.8 = 24.1** - **K - 273 = 24.1** - **K = 297.11...

# Matter and Measurements - **T(°F) = 1.8 T(°C) + 32°** - **T(K) = T(°C) + 273.15** **Example**: The temperature of a system is measured to be 75.4°F. An equivalent temperature would be: - **K - 273 = (F - 32) / 1.8** - **(75.4 - 32) / 1.8 = 24.1** - **K - 273 = 24.1** - **K = 297.11** - **180C = (7540 - 3200) / 1.8** - **180C = 4340** - **C = 24.1** # Rules of Significant Figures: 1. All non-zero digits are significant. 2. All zeros between non-zero digits are significant. 3. All zeros to the right of a non-zero digit and a decimal are significant. 4. Zeros to the left of non-zero digits are not significant. 5. Zeros to the right of a non-zero digit but have no decimal are not significant. **Examples**: - **10.2341,** **3000** have 5 significant figures. - **0.052** has two significant figures. - **39.0** has three significant figures. - **35P** has two significant figures. **In multiplication and division, the final result should have the same number of significant figures as the number with the fewest significant figures**. **In addition and subtraction, the final result should have the same number of decimal places as the number with the fewest decimal places**. # The Best Answer of... * 0.578 x 0.435 + 0.28 is **0.49** (answer rounded to two decimal places). * 12.34 x 1.23 = 15.2 (answer rounded to three significant figures). * 0.009967 = 0.00997 (answer rounded to three significant figures). * 37.24 + 1013 = 1002 (answer rounded to the least number of digits). * 225.618 + 0.23 = 225.85 (answer rounded to the least number of decimal places). * 2.561 x 12.35 + 0.31 is **1.20** (answer rounded to two decimal places). * Calculate the best value of X: **X = 67 ** # Conversions - 1 foot = 12 inches - 1 meter = 100 cm - 1 atm = 1.01325 x 10⁵ Pa = 760 torr **Example:** How many cm are in 1.32 meters? - 1.32 meters x (100 cm/1 meter) = **132 cm** **Example:** How many meters are in 8.72 cm? - 8.72 cm x (1 meter / 100 cm) = **0.0872 meters** **Example:** If a gas in a gas cylinder has a pressure of 91.4 atm, its value could also be recorded as: - 91.4 atm x (1.01325 x 10⁵ Pa/1 atm) = **9.26 x 10⁶ Pa** - 91.4 atm x (760 torr/1 atm) = **69.4 x 10³ torr**