Unit Conversions and Density Quiz

Unit Conversions

• 1 oz = 29.6 ml
• 1 ft^3 = 28.32
• 1 m^3 = 35.3 ft^3
• 1 yd^2 = 0.836 m^2
• 1 cm^2 = 0.155 in^2
• 1 km^2 = 1.196 x 10^6 yd^2
• 1 acre = 4840 yd^2 = 4046.556 m^2
• 1 hectare (ha) = 2.471 acres = 10,000 m^2
• 1 calorie (cal) = 4.184 joules (J)
• 1 British Thermal Unit (BTU) = 252 cal = 1055 J
• 1 Pascal (Pa) = 1 kg/m s^2
• 1 kPa = 1000 Pa
• 1 atmosphere (atm) = 760 torr = 760 mm Hg = 101,325 Pa = 14.7 in Hg

Mass & Weight

• Mass measures the amount of matter in an object or substance and is constant throughout the universe.
• Weight measures the effect of the gravity (attraction from another body) on an object.
• Weight is related to mass, but varies depending on the gravitational force exerted on the object.

Density

• Density (ρ) is the amount of mass per volume of a substance.
• It can be used to identify different substances and is calculated as:
  • ρ = m/V
• The density of water at 4°C is 1.0000 g/mL, 1.0000 g/cm^3, 1000.00 kg/m^3, or 62.4 lb/ft^3.
• The specific gravity (sp gr) of a substance is the ratio of its density to the density of water at 4°C.
• It tells how many times heavier a substance is compared to water:
  • sp gr = density of sample / density of water
• An object denser than water will sink, while a less dense object will float.

Temperature

• The Fahrenheit scale commonly used in the US defines water's freezing and boiling points as 32°F and 212°F, respectively.
• The Celsius scale (often called Centigrade) defines water's freezing and boiling points as 0°C and 100°C, respectively.
• The Kelvin scale is an absolute scale for measuring temperature.
  • Temperature conversions:
    • T°C = (5/9)(T°F - 32)
    • T°F = (9/5)T°C + 32
    • T°R = T°F + 460
    • TK = T°C + 273

Chemical Safety

• Chemical safety focuses on minimizing risks associated with handling chemicals and chemical processes.
• It involves understanding the physical, chemical, and toxicological hazards of chemicals.
• Chemical safety aims to protect human health and the environment from the hazards of chemicals.
• Key aspects of chemical safety:
  • Identify the hazard: Identify the chemicals in the workplace and their associated hazards.
  • Assess the risk: Evaluate the risks posed by chemicals or processes in the workplace.

Toxic Chemical Examples

• Hydrogen cyanide gas: Passes through the skin and lungs, prevents oxygen delivery to the brain and heart, and blocks cell respiration.
• Organic solvents: Often flammable and can be inhaled or absorbed through the skin.
  • Benzene: Can cause leukemia.
  • Carbon tetrachloride: Causes severe liver damage.
  • Carbon disulfide: Affects the brain and nervous system.

Acids & Bases

• Acids and bases are corrosive. The severity of damage depends on concentration and exposure duration.

Strong Acids

• Have a pH less than 4 and can cause chemical burns.
• Some strong acids are hydrochloric, nitric, sulfuric, and phosphoric acids.
• Weak acids (acetic, citric, carbonic) are not corrosive and can be consumed safely.

Strong Bases

• Have a pH greater than 10 and can cause chemical burns.
• Some strong bases are calcium hydroxide, sodium hydroxide, and potassium hydroxide.
• Weak bases like ammonia and sodium bicarbonate are less harmful.

Test your knowledge on unit conversions, mass, weight, and density with this quiz. Understand the differences between mass and weight, how density is calculated, and the various units that measure these properties. Perfect for students diving into physics and physical science concepts.