Chemistry Basics
What is the difference between mass and weight?
Mass = amount of matter
weight = mass + effect of gravity
What are the units used for mass, volume, and distance/length?
mass = grams
Volume = ml or liter (example)
Distance = meters
What are the 3 common states of matter?
Solid, liquid, gas
Cutting wood is what type of change? physical or chemical?
No stealing on this question
Physical change
Does changing the volume of water change its density?
No density stays the same
Give one example of qualitative data and one of quantitive data.
Example
Qualitative = color of a liquid.
Quantitative = temperature of 25°C
Express 350,000 in scientific notation.
3.5 x 105
Define extensive property and give an example.
Depends on the amount of matter
Example = mass, volume etc
Cooking an egg is what type of change? physical or chemical?
No stealing on this question
Chemical change
Chromatography showed that ink separated into colors. Does this mean ink is a compound or a mixture?
a mixture
what is the independent variable in an experiment?
The variable the scientist changes.
Solve (5 × 10⁻⁵) + (2 × 10⁻⁵)
On a piece of paper write your answer. you have 2 min.
7 × 10⁻⁵
Define intensive property and give an example.
Does not depend on the amount of matter.
Example = density, boiling point etc.
What law states that matter is neither created nor destroyed in a chemical reaction?
Law of conservation of mass
Why did pre-1982 pennies have a different density than post-1982 pennies?
Pre-1982 pennies were mostly copper; post-1982 are mostly zinc (metal) with copper coating.
Which variable is responding to an intentional change; the variable the scientist is measuring?
Independent variable or dependent variable?
No stealing on this question
Dependent Variable
If 1 gallon = 4 quarts and 1 L = 0.908 quarts, how many liters are in 2 gallons?
On a piece of paper write your answer. you have 4 min.
8.8 L
What is the difference between vapor and gas?
Gas = naturally gaseous at room temp
Vapor = gaseous form of something normally liquid/solid at room temp.
Provide a sign of a chemical change occurring.
Fizzing, temperature change, release of light, color change, odor change
In the cornstarch lab, the mixture sometimes acted like a solid and sometimes like a liquid. Is this mixture homogeneous or heterogeneous?
Heterogeneous — the mixture does not have a uniform composition throughout.
A scientist tests fertilizer on plant growth. Identify the independent variable, dependent variable, and control group.
Independent = fertilizer
Dependent = plant growth
Control = plants with no fertilizer.
A runner drinks 2 bottles of water during practice. Each bottle holds 500 mL. 1 l = 1000 ml
How many liters of water did the runner drink?
On a piece of paper write your answer. you have 4 min.
1 L
What is the difference between homogenous and heterogenous mixtures?
Homogeneous = uniform composition (salt water, air). Heterogeneous = not uniform (sand and water, salad).
The composition of H2O does not change, only the state changes.
In your own words, explain the difference between a closed system and an open system in the Conservation of Mass lab.
Closed = nothing enters or leaves, so mass stays the same. Open = gas can escape, so measured mass may decrease.