Unit 2 – Measurement and Experimental Techniques

Vocabulary flashcards covering key terms and apparatus from Unit 2: Measurement and Experimental Techniques, including SI base units, measuring devices, volume reading practices, gas collection methods, and common unit conversions.

Physical Quantity

Any measurable property of an object or phenomenon, expressed with a numerical value and a unit (e.g., length, mass, time).

Unit

A standard reference used to express and compare the magnitude of a physical quantity.

International System of Units (SI)

Globally accepted metric system of measurement based on seven base units.

Base Unit

A fundamental SI unit that is independent of other units, such as meter or kilogram.

Derived Unit

A unit obtained from combinations of base units (e.g., m/s for speed).

Meter (m)

SI base unit of length.

Kilogram (kg)

SI base unit of mass.

Second (s)

SI base unit of time.

Kelvin (K)

SI base unit of temperature; related to Celsius by T(K) = T(°C) + 273.

Ampere (A)

SI base unit of electric current.

Mole (mol)

SI base unit for amount of substance.

Candela (cd)

SI base unit of luminous intensity.

Beam Balance

Mechanical apparatus used to compare masses using counterweights.

Electronic Balance

Digital device that measures mass electronically with high precision.

Analog Stopwatch

Timing instrument with a dial and hand; accuracy limited by human reaction time.

Digital Stopwatch

Electronic timer that displays elapsed time numerically; offers greater accuracy than analog versions.

Thermometer

Instrument for measuring temperature, commonly mercury- or alcohol-filled glass tubes.

Temperature Sensor with Data Logger

Electronic probe connected to a recording device for high-accuracy temperature measurements.

Graduated Cylinder

Tall, narrow vessel with volume markings for measuring liquid volumes; read at eye level at the meniscus.

Meniscus

Curved upper surface of a liquid in a container; correct volume is read at the bottom of the curve.

Burette

Long, graduated glass tube with a stopcock, used to deliver precise liquid volumes in titrations.

Pipette

Glass or plastic tube calibrated to deliver a fixed volume of liquid accurately.

Gas Syringe

Graduated syringe used to collect and measure the volume of gases produced in reactions.

Displacement of Water

Gas collection technique where an insoluble gas displaces water from an inverted container.

Downward Delivery

Method of collecting gases denser than air by allowing them to flow downward into a container.

Upward Delivery

Technique for collecting gases less dense than air by letting them rise into an inverted container.

Quicklime (CaO)

Drying agent used to remove moisture from ammonia gas.

Fused Calcium Chloride (CaCl₂)

Desiccant employed to dry hydrogen and other gases.

Concentrated Sulfuric Acid (H₂SO₄)

Powerful dehydrating agent for drying hydrogen chloride gas.

Tonne (t)

Metric mass unit equal to 1,000 kilograms; used for very heavy objects.

Gram (g)

Non-SI unit of mass equal to 1⁄1,000 of a kilogram; suitable for small masses.

Degree Celsius (°C)

Common temperature scale where 0 °C is the freezing point of water.

Cubic Meter (m³)

SI derived unit of volume.

Cubic Decimeter (dm³)

Volume equal to one liter; 1 dm³ = 1 L.

Cubic Centimeter (cm³)

Small volume unit; 1 cm³ = 1 mL.

Liter (L)

Common unit of liquid volume equal to 1 dm³.