Accuracy vs. Precision
Lab Safety
Endo vs. Exothermic Reactions
Dimensional Analysis
Wild Card
100
Define Accuracy.
How close a measurement is to a true and accepted value.
100
What is the first thing you should do when entering the lab?
Read directions!!! This will tell you what safety gear you need.
100
Define Endothermic reactions.
Endothermic reactions are reactions that absorb energy (usually in the form of heat) from its surroundings, this causes the system to gain energy.
100
What is the conversion from liters to milliliters?
1L=1000mL
100
What is kinetic energy?
Energy in motion
200
Define Precision
how close repeated measurements are to each other, showing consistency and repeatability, but not necessarily how close they are to the true or correct value
200
Jimmy is working with his lab partner Kayla, they are using a bunsen burner to light a cheeto on fire and see the energy that is being released. What type of lab safety equipment do they need?
Goggles!! Gloves would be a plus too.
200
Define Exothermic reactions.
This type of reaction occurs when the system releases energy (usually in the form of heat) to its surroundings causing the system to lose energy.
200
What does King Henry Died Monday Drinking Chocolate Milk stand for?
Killo, Hecto, Deca, Metric Unit, Deci, Centi, Milli
200
What type of energy is defined as the kinetic energy of the atoms of a substance?
Thermal energy
300
Does this target show accuracy or precision?
Accuracy and precision
300
Lola is working in the lab with a chemical when it splashes up into her eye!! She runs to the eye wash station. What should she do next?
Place her eyes onto the spout openings and rinse them for 15 minutes.
300
What type of graph is shown above? Explain.
Endothermic, the reactant has less energy than the product. It gains energy in the reaction.
300
Covert 20mL to L using dimensional analysis.
0.02L
300
Sophia is heating water in a kettle on an electric stove. She develops a model to determine the energy transferred to the water by the heating element. Which assumption will Sophia need to make in order for her model to be considered a closed system?
No heat is lost from the stove or the kettle, only transferred
400
A group of students measured the mass of a sample four times. The true mass of the sample is 50.0 g. Their results are shown below:
Trial 1: 47.8 g
Trial 2: 47.9 g
Trial 3: 47.7 g
Trial 4: 47.8 g
Which statement best describes their measurements?
Precise but not accurate
400
Sam and Peyton are working the lab on an experiment. Sam notices a chip in the beaker they are using and it looks sharp. What should Sam and Peyton do?
They should let a teacher know and throw the beaker away in the glass disposal.
400
What type of reaction is this?
2H2(g) + O2 (g) -> 2H2O (g) + energy
Exothermic, the equation shows that the reactant has released the energy therefore it becomes apart of the product side.
400
A grocery store receives a shipment of rice weighing 18,750 grams. The manager needs the weight written on the inventory sheet in kilograms. What is the mass of the rice in kilograms?
18.75kg of rice
400
At the start of a magnesium combustion experiment, the combined mass of magnesium ribbon and oxygen reactants was 20 grams. At the end of the reaction, a solid white ash left on the scale was 20 grams. Why does the scale show the same amount of mass even though the substance has changed. (Refer to your review for image and answer choices)
The conservation of mass states that mass cannot be created nor destroyed in a chemical reaction.
500
Is this target precise or accurate?
Neither
500
Nicole and Addison are working with water and acid in the lab today. They are two mix the two to see what type or reaction occurs. How should they mix the two in order to ensure it is safe?
Add acid to the water
500
Biology students are studying the process that takes place in a plant's chloroplasts during photosynthesis. Light energy is absorbed by chlorophyll and used to convert carbon dioxide and water into glucose and oxygen. The plant stores energy in the form of glucose. What type of exothermic or endothermic reaction occurred during this process?
Endothermic Reaction
500
An astronomer measures the rotation period of a distant planet as 250,000 seconds. How many days is this equal to?
2.89 days
500
In a laboratory experiment, a piece of ethanol was burned inside a sealed metal container. The total mass of the container and its contents before burning was 150 g, and after burning, the mass remained 150 g. During the combustion, the temperature inside the container rose significantly, and the outside of the container also became hot to the touch.
Is this container an example of an open system, a closed system, or an isolated system?
Closed system