Analytical Chemistry Lesson 02

Which of the following is the SI unit for mass?

Weight is the measure of the quantity of matter in an object.

What is the formula for calculating weight (w)?

Match the following measurement units with their corresponding physical quantities:

The ratio of mass to volume of a substance is known as ______.

Specific gravity is defined as the ratio of the density of a substance to the density of which standard?

The standard density for water is 1.00 g/mL at 25°C.

What does 'g' represent in the equation w = mg?

Which of the following temperature scales is not a conventional scale for measuring temperature?

What is the SI unit for the amount of a substance?

The boiling point of water is the same on all temperature scales.

The mass of a substance in grams of a mole of that substance is called its _____ mass.

Match the following terms with their definitions:

How is the number of moles of a substance calculated?

Heat only flows from colder to hotter bodies.

What is the primary relationship between mass, particles, and volume according to the flowchart described?

International System of Units (SI Units)

Standardized system of measurement used globally.
Consists of seven base units for different physical quantities.

SI Base Units

Mass: Kilogram (Kg)
Length: Meter (M)
Time: Second (S)
Temperature: Kelvin (K)
Amount of Substance: Mole (Mol)
Electric Current: Ampere (A)
Luminous Intensity: Candela (cd)

Mass vs. Weight

Mass is the invariant measure of matter quantity; does not change with gravity.
Weight is the gravitational force on an object: ( w = mg ) where ( w ) is weight, ( m ) is mass, and ( g ) is gravitational acceleration.

Density

Density serves as a "fingerprint" for substances; calculated by mass divided by volume:
[ \text{density} = \frac{\text{mass}}{\text{volume}} ]
Related to specific gravity, defined as:
[ \text{Specific gravity} = \frac{\rho_{\text{substance}}}{\rho_{\text{standard}}} ]
Standard densities:
- Solids and liquids: ( \rho_{\text{water}} = 1.00 \text{ g/mL} )
- Gases: ( \rho_{\text{air}} = 0.001 \text{ g/mL} )

Temperature

Indicates the degree of hotness and the total heat content in an object.
Heat flows from hot to cold regions due to temperature difference.
Measured using three conventional scales: Celsius, Fahrenheit, and Kelvin.

Mole

SI unit for measuring the amount of a chemical substance; directly proportional to the number of particles.
Molar mass: mass (in grams) of one mole of a substance.
Relationship between mass, moles, and molar mass expressed as:
[ n_X = \frac{m_X}{M_X} ]
where ( n_X ) is moles, ( m_X ) is mass, and ( M_X ) is molar mass.

Relationships in Mole Calculations

Mass, particle count, and volume of gases at Standard Temperature and Pressure (STP) are interrelated via formulas.
A flowchart establishes the links between mass, particle count, and volumes for various substances.

Explore the fundamentals of calculations in Analytical Chemistry with a focus on the International System of Units (SI). This lesson covers SI Base Units, their definitions, and applications in scientific measurements, essential for any chemistry student. Enhance your understanding of physical quantities and their standardized units.