01/14 Foundations of Chemistry and Quantitative Reasoning Free Online FlashCards

What is matter?

Matter is anything that has mass and occupies space.

How do elements and compounds differ?

An element contains one type of atom; a compound contains two or more elements chemically combined in fixed ratios.

Accuracy versus precision

Accuracy is closeness to an accepted value, whereas precision is agreement among repeated measurements.

Which quantities are extensive or intensive?

Mass and volume are extensive because they depend on sample size; density and temperature are intensive because they do not.

What two parts make up a measurement?

A measurement requires both a numerical value and a unit; the unit identifies what the number means.

What is the SI unit of temperature?

The kelvin is the SI unit for thermodynamic temperature, and kelvin values are written without a degree symbol.

Find the density of 39.6 g occupying 30.0 mL.

Density is mass divided by volume: ρ = m/V = 39.6 g ÷ 30.0 mL = 1.32 g/mL.

Convert 25.00 °C to kelvin.

Convert Celsius to kelvin by adding 273.15: 25.00 °C + 273.15 = 298.15 K.

How are significant figures handled in multiplication?

For multiplication and division, the result has the same number of significant figures as the factor with the fewest significant figures.

Round 12.11 + 0.3 + 4.567 correctly.

For addition, round to the fewest decimal places: 12.11 + 0.3 + 4.567 = 16.977, which becomes 17.0.

Convert 2.50 km to meters.

2.50 km × (10³ m/1 km) = 2.50 × 10³ m. The kilometer units cancel.

What is dimensional analysis?

Dimensional analysis converts quantities by multiplying by conversion factors equal to one, allowing unwanted units to cancel.