Describing Matter
Anything that has mass and occupies space is called __________.
Matter
Matter that has a definite and uniform composition is called a __________.
Pure substance
Which laboratory instrument would be most appropriate for measuring 25.0 mL of water accurately?
A. Balance
B. Graduated cylinder
C. Meter stick
D. Thermometer
B — Graduated cylinder
According to Boyle's Law, when temperature remains constant, what happens to the volume of a gas when pressure increases?
Pressure and volume have an inverse relationship.
A sample has:
Mass = 60.0 g
Density = 3.00 g/mL
Determine its volume.
V = m/D
V = 60.0/3.00
V = 20.0 mL
A student observes that a sample of copper is reddish-brown, shiny, and solid at room temperature.
Are these observations physical properties or chemical properties?
Physical properties
Classify each substance as an element, compound, homogeneous mixture, or heterogeneous mixture.
A. Oxygen gas: __________________________
B. Salt water: __________________________
C. Carbon dioxide: ______________________
D. Salad: ______________________________
A. Element
B. Homogeneous mixture
C. Compound
D. Heterogeneous mixture
Use a balance to determine the mass of a St Agnes Planner
Measured Mass: __________________ g
about 320.5 grams
A gas occupies 4.0 L at 1.5 atm. The gas is compressed until its pressure reaches 3.0 atm.
Calculate the new volume.
(1.5 atm)(4.0 L) = (3.0 atm)(V₂)
6.0 = 3.0V₂
V₂ = 2.0 L
An unknown metal has:
Mass = 53.4 g
Volume = 6.00 cm³
Calculate the density
Density: __________________ g/cm³
D = 53.4/6.00
D = 8.90 g/cm³
A metal sample has the following characteristics:
Identify two quantitative properties and one qualitative property.
Quantitative examples: mass of 54.0 g; volume of 20.0 mL; melting point of 660°C
Qualitative: silver color
A beaker contains water with salt completely dissolved in it.
A rectangular metal block measures:
Calculate its volume
V = l × w × h
V = 5.0 × 3.0 × 2.0
V = 30 cm³
A balloon has a volume of 2.50 L at 300 K. It is heated to 360 K while pressure remains constant.
Calculate the new volume.
2.50/300 = V₂/360
V₂ = 3.00 L
Answer: 3.00 L
A student places a capped syringe containing air under increasing pressure.
The student records:
Pressure & Volume
Questions
A student burns a strip of magnesium and observes that a bright white light is produced and a new white solid forms.
Is this primarily a physical change or a chemical change? Explain your reasoning.
Chemical change because a new substance forms during the reaction.
A student is given four unknown samples.
Classify each sample.
A: ____________________________________
B: ____________________________________
C: ____________________________________
D: ____________________________________
A. Element
B. Compound
C. Homogeneous mixture
D. Heterogeneous mixture
A metal sample has a mass of 78.0 g and a volume of 10.0 cm³.
Calculate its density.
D = m/V
D = 78.0/10.0
D = 7.80 g/cm³
A gas occupies 3.50 L at 1.20 atm and 300 K.
The pressure changes to 0.90 atm and the temperature increases to 350 K.
(1.20)(3.50)/300 = (0.90)(V₂)/350
V₂ ≈ 5.44 L
The state of matter where the particles move around and take on the SHAPE of their container, but don't always fill it
Liquid
A substance has the following properties:
Classify each property as physical or chemical.
Density — Physical
Melting point — Physical
Reacts with oxygen — Chemical
Conductivity — Physical
Malleability — Physical
A student receives a mixture containing iron filings, sand, and salt.
Describe a logical procedure for separating all three substances.
Use a magnet to remove the iron. Add water to dissolve the salt. Filter the mixture to separate the sand from the salt solution. Evaporate the water to recover the salt.
An irregular object is placed into a graduated cylinder.
Initial water volume = 42.0 mL
Final water volume = 58.5 mL
Mass of object = 131.2 g
A. Calculate the volume of the object.
B. Calculate its density.
Volume = 58.5 − 42.0
Volume = 16.5 cm³
Density = 131.2 ÷ 16.5
Density ≈ 7.95 g/cm³
A weather balloon contains 9.50 L of gas at a temperature of 19°C. The balloon is heated by sunlight until the gas temperature reaches 35°C, while the external pressure remains constant. The flexible balloon is able to expand freely as the gas warms. Calculate the new volume of the balloon.
2929.50=308V2
Solve:
V2=(9.50)(308)292V2=10.02L
Final Answer: 10 L
The temperature inside a greenhouse reaches 104°F during a warm afternoon. What is this temperature in degrees Celsius?
57.8 C or 58 C