density worksheet answer key chemistry

Lemon

2 min read

·

04-02-2025

1

0

Share

This comprehensive guide provides answers and explanations for a typical chemistry density worksheet. Understanding density is fundamental in chemistry, allowing us to explore the relationship between mass, volume, and the properties of matter. We'll break down the concepts and provide solutions to various density problems, ensuring a solid grasp of this crucial topic.

What is Density?

Density (ρ, pronounced "rho") is a physical property of a substance that represents the mass per unit volume. It's a measure of how tightly packed the matter is within a given space. The formula for density is:

ρ = m/V

Where:

• ρ represents density (usually in g/cm³ or g/mL)
• m represents mass (usually in grams, g)
• V represents volume (usually in cubic centimeters, cm³, or milliliters, mL)

Common Density Problems & Solutions

Let's tackle some common density problems and their solutions. Remember, always include units in your calculations and answers!

Problem 1: A piece of metal has a mass of 25 grams and a volume of 5 cubic centimeters. What is its density?

Solution:

1. Identify knowns: m = 25 g, V = 5 cm³
2. Apply the formula: ρ = m/V = 25 g / 5 cm³
3. Calculate: ρ = 5 g/cm³

Answer: The density of the metal is 5 g/cm³.

Problem 2: A liquid has a density of 0.8 g/mL and a volume of 100 mL. What is its mass?

Solution:

1. Identify knowns: ρ = 0.8 g/mL, V = 100 mL
2. Rearrange the formula to solve for mass: m = ρV
3. Calculate: m = 0.8 g/mL * 100 mL
4. Calculate: m = 80 g

Answer: The mass of the liquid is 80 grams.

Problem 3: A block of wood has a mass of 150 grams and a density of 0.75 g/cm³. What is its volume?

Solution:

1. Identify knowns: m = 150 g, ρ = 0.75 g/cm³
2. Rearrange the formula to solve for volume: V = m/ρ
3. Calculate: V = 150 g / 0.75 g/cm³
4. Calculate: V = 200 cm³

Answer: The volume of the wood block is 200 cubic centimeters.

Problem 4 (Advanced): A graduated cylinder contains 50 mL of water. When a 20-gram metal object is submerged, the water level rises to 65 mL. What is the density of the metal object?

Solution:

1. Calculate the volume of the metal object: The water level rose by 65 mL - 50 mL = 15 mL. This is the volume of the metal object (assuming no significant water displacement from the object itself).
2. Identify knowns: m = 20 g, V = 15 mL
3. Apply the formula: ρ = m/V = 20 g / 15 mL
4. Calculate: ρ ≈ 1.33 g/mL

Answer: The density of the metal object is approximately 1.33 g/mL.

Beyond the Basics: Factors Affecting Density

Several factors can influence the density of a substance:

• Temperature: Density usually decreases as temperature increases (exceptions exist).
• Pressure: Increased pressure generally leads to increased density.
• Composition: Different substances have different densities due to their unique atomic structures and molecular arrangements.

This worksheet and its solutions provide a strong foundation for understanding density calculations. Remember to practice regularly to master these fundamental chemistry concepts. Consistent practice with different problem types will solidify your understanding and prepare you for more complex chemistry challenges.