Definitions
What is a control or controlled variable?
A control is a variable that is kept constant from one experiment to the next
What is 546007 in scientific notation?
5.46007 x 10^5
What is energy?
Energy is the ability to do work, like moving an object, forming a compound, or generating heat or light
What is a hypothesis?
A testable prediction/explanation
If 5.046 L of water is mixed with 2.6 L of hydrogen peroxide, what is the final volume of the mixture? (Hint: Use significant figures)
7.6 L
What is the Law of Conservation of Mass?
The Law of Conservation of Mass states that the products of a chemical reaction have the same mass as the starting reactants (mass is neither created nor destroyed, only changed in form)
What is 0.00000082 in scientific notation?
8.2 x 10^-7
What does the Law of Conservation of Energy state?
The Law of Conservation of Energy states that during any physical or chemical change, the total amount of energy remains the same
This means that energy cannot be created or destroyed, only transformed
What are the steps of the scientific method?
Observe, Question, Form a hypothesis, Conduct an experiment, Analyze results, Draw conclusions, Report results
If the mass of a sample of gold is 96.6 grams and its volume is 5 cm^3, what is its density? (D=m/v) (Hint: use significant figures)
20 g/cm^3
What is a model?
A model represents an object, system, process, or idea in a simple and useful way
How many significant figures are in 0.00501600
6
What is the difference between endothermic and exothermic reactions?
Endothermic reactions absorb energy and exothermic reactions release energy
What is the difference between a theory and a law?
a theory is a well-tested explanation of observations while a law is a statement or mathematical expression that reliably describes the behavior of the natural world.
a hypothesis predicts events, a theory explains events, and a law describes events
How much heat energy is needed to heat 10.2 grams of water from 25 C to 45 C? (The specific heat capacity of water is 4.186 J/gC) (q=mCAT)
850 J
What is the difference between a system and surroundings?
A system is anything that is being studied
The surroundings is anything outside of the system
How many significant figures should the answer to the problem below have?
7.0245 + 0.1
2
(7.1)
What is the difference between heat energy, kinetic energy, and temperature?
Heat is the energy transferred between objects that are at different temperatures, while Kinetic energy is the energy of motion (or the energy of an object that is in motion). Temperature measures the average kinetic energy of the movement of particles in a substance
What is an independent variable?
An independent variable is what is being tested or changed during the experiment
What is the final temperature when 609 J is applied to 25.9 grams of water at 25 C? (The specific heat of water is 4.186 J/gC) (q=mCAT) (Hint: use significant figures)
31 C or 3.0 x 10^2 K
What is the difference between accuracy and precision?
Accuracy is how close a measurement is to the true or actual value while precision is how closely several measurements agree with each other
How many significant figures should the answer to the problem below have?
8.000 x 0.0005
1
(0.004 or 4.0 x 10^-3)
How does temperature change when heat is added to a substance as it changes from solid to liquid to gas?
the temperature only increases when the substance is in the solid, liquid, or gas phase, and not when it is moving between phases
What is a dependent variable?
A dependent variable is what is being measured at the end of an experiment; it depends on the independent variable
How much heat energy is needed to heat 15.5 mL of water from 0 C to 100 C? (The density of water is 1.000 g/mL and the specific heat of water is 4.186 J/gC) (q=mCAT)
6000 J