Physical/Chemical Properties
Frying an egg is an example of a ______ change.
What is the formula for calculating density?
Density = Mass/Volume
What type of reaction does the following chemical equation represent:
Cl₂ + 2NaBr → 2NaCl + Br₂
Single Displacement.
When baking soda is mixed with vinegar, carbon dioxide gas is produced. If the total mass of the baking soda and vinegar before the reaction is 25 g, what should the total mass of all products be after the reaction?
25 g
What types of reactions does combustibility deal with?
Fire, explosions, burning, etc.
Calculate the density for the object using the given mass and volume.
Mass = 25 g, Volume = 5 cm³
5 g/cm3
Which of the following would decrease the rate of a reaction:
-increasing the temperature
-increasing the surface area
-decreasing the amount of reactants
-the type of beaker used for the reaction
Decreasing the amount of reactants.
How does balancing equations support the Law of Conservation of Mass?
It ensures that the number of atoms of reactants is the same as the number of atoms of products.
Which of these is not a clue that a chemical reaction is taking place:
-phase change
-gas bubbles
-precipitate formation
-permanent color change
Phase Change
A liquid has a density of 4.5 g/cm³ and completely fills a container with a volume of 250 cm³.
What is the mass of the liquid in the container?
1125 g
Increasing the temperature of a chemical reaction causes the particles of the reactants to move faster. What does this do to the rate of the reaction?
It makes the reaction faster.
Does the following equation support the Law of Conservation of Mass? Why?
C₂H₆ + O₂ → CO₂ + H₂O
No - the products and reactants are not balanced.
Gas bubbles from a chemical reaction indicate a ______ change, while gas bubbles from boiling indicate a _______ change.
chemical, physical
A student places an unknown rock into a graduated cylinder that initially contains 40.0 mL of water. After the rock is fully submerged, the water level rises to 57.2 mL. If the rock has a mass of 48.5 g, what is its density?
2.82 g/mL
Doctors generally don't reccomend crushing up solid pills into powder because it causes them to react in the body too fast. Why might the powder react faster than the solid pill?
The powder has an increased surface area.
Balance the following equation:
__ NaOH + __ H₂SO₄ → __ Na₂SO₄ + __ H₂O
2 NaOH + H₂SO₄ → Na₂SO₄ + 2 H₂O
A researcher is comparing two clear, odorless substances. Substance A boils at 120°C and remains unchanged when a piece of magnesium is added. Substance B boils at 65°C and produces gas bubbles when magnesium is added. Why do the two substances react differently?
They have different chemical properties.
A scientist finds a mysterious solid with a density of 19.3 g/cm³. If the mass of the sample is 115.8 g, what is its volume?
6 cm3
Oil has significantly lower surface tension than water. What can be said about the particles of oil?
They are further apart than water particles.
A reaction occurred in an open container, in which the gas produced was able to escape. What might happen to the mass of the products?
The mass of the products will be less than the mass of the reactants.