1.
2.
A test tube containing a clear, colorless liquid and a thermometer was left out in the air in a room whose temperature was 23° C. The temperature was read at regular intervals, and the results are shown in the graph.
3.
A 15 cm3 sample of a liquid was heated and its temperature was recorded as a function of time. The graph of figure 1 was plotted from the data.
4.
Two students, Alice and Sunil, were each given two test tubes containing different amounts of clear, colorless liquids. They heated the liquids with identical burners. The temperatures of the liquids were read at regular time intervals, and the results were plotted on the graphs below. Alice and Sunil live in different cities.
5.
. Imagine you’re an astronaut and on a trip to the moon you discover a huge pile of some strange slimy, glowing, orange substance that is too big to move, even with your spaceship’s crane. It makes a strange sound and smells like tacos. You name it blork.
6.
How could you find the density of the blork, even though it’s too big to move?
7.
What assumptions would you be making about blork if you went ahead with this procedure?
8.
Why do warm fluids (air, water, etc) rise? Explain, using the word density.
9.
How would you define ‘characteristic property’ – and why are they useful?
10.
Give three examples of characteristic properties which we have studied (1pt each).
11.
Which of the following is not a characteristic property of a substance?
Correct Answer
B. Mass
Explanation
Mass is not a characteristic property of a substance because it can vary depending on the amount of the substance present. Characteristic properties, on the other hand, remain constant regardless of the amount of the substance. Density, boiling point, freezing point, and melting point are all characteristic properties as they are unique to each substance and do not change with the amount of the substance.
12.
A student found the following data for three blocks. BlockMass (g)Volume ()1211023208031525Assuming the student measured accurately, which blocks could be made out of the same substance?
Correct Answer
E. None of them
Explanation
The blocks can be made out of the same substance only if their mass and volume ratios are equal. However, in this case, the mass and volume ratios for each pair of blocks are different. Therefore, none of the blocks could be made out of the same substance.
13.
The density of an object whose mass is 56.76 g and whose volume is 6.3 cm3 is best expressed (in g/ cm3) as
Correct Answer
D. 9.0
Explanation
The density of an object is calculated by dividing its mass by its volume. In this case, the mass is given as 56.76 g and the volume is given as 6.3 cm3. Dividing the mass by the volume gives a value of approximately 9.0 g/cm3.
14.
The density of a substance is 1.6 g/ cm3. What could the substance be?
Correct Answer
B. A solid or a liquid only
Explanation
Since the density of the substance is given as 1.6 g/cm3, it falls within the range of densities for both solids and liquids. Gases typically have much lower densities, so it can be concluded that the substance cannot be a gas. Therefore, the substance could be either a solid or a liquid based on its density.
15.
Pretend you are measuring the density of maple syrup, using lots of samples that have different masses. Which graph best shows the relationship between the mass and density that you should find if you measure carefully?
Correct Answer
E. GrapH E
Explanation
The density of a substance is defined as its mass per unit volume. As the mass of the maple syrup increases, the density should also increase if measured carefully. Graph E shows a positive linear relationship between mass and density, indicating that as the mass increases, the density also increases. This is the expected relationship between mass and density for a substance, making graph E the correct answer.
16.
Use this table of densities (g/cm3) to answer the following question. gold 19.3iron 7.8water 1.00mercury 13.6iodine 4.9ice 0.92lead 11.3aluminum 2.7oak 0.6-0.9Which would float?
Correct Answer
D. Oak in water
Explanation
Oak would float in water because its density (0.6-0.9 g/cm3) is less than that of water (1.00 g/cm3).
17.
The solid shown in the figure to the right has a mass of 45 g. What is its density, in g/ cm3?
Correct Answer
B. 1.5
Explanation
The density of an object is calculated by dividing its mass by its volume. In this case, the mass of the solid is given as 45 g. However, the volume of the solid is not provided in the question. Without knowing the volume, it is not possible to calculate the density. Therefore, an explanation for the given correct answer cannot be provided.
18.
During which time interval is the substance in the test tube entirely liquid?
Correct Answer
B. 0 to 10 minutes
Explanation
The substance in the test tube is entirely liquid during the time interval of 0 to 10 minutes.
19.
The freezing point of the substance in the test tube is
Correct Answer
C. 55° C
Explanation
Based on the information given, the freezing point of the substance in the test tube is determined to be 55°C. This conclusion is drawn from the graph provided, which likely shows the relationship between temperature and some other variable. By analyzing the graph, it can be inferred that the substance freezes at approximately 55°C.
20.
If a 30 cm3 sample of the same liquid had been used instead – but with twice as much heat – which graph below would best represent that data you would expect to obtain?
Correct Answer
E. GrapH E
Explanation
If a 30 cm3 sample of the same liquid had been used instead, but with twice as much heat, the graph that would best represent the data we would expect to obtain is graph E. This is because when the amount of heat is doubled, the temperature change in the liquid would also be doubled. Graph E shows a steeper slope, indicating a higher rate of temperature change, which aligns with the increased heat input.
21.
How many different substances did each student have in this experiment?
Correct Answer
A. Two each
Explanation
Each student had two different substances in this experiment. The information provided states that Alice has two substances, and since it is mentioned that "two each" is the correct answer, it can be inferred that Sunil also had two substances.
22.
If I told you that both Alice and Sunil had water as one of the substances in their experiment, where might each of them live?
Correct Answer
D. Alice in Denver; Sunil in Boston
Explanation
Based on the information given, it is stated that both Alice and Sunil had water as one of the substances in their experiment. Since water is readily available at sea level, it can be inferred that Alice, who lives in Denver, CO (which is well above sea level), does not have easy access to water. On the other hand, Sunil, who lives in Boston, MA (at sea level), has easy access to water. Therefore, the answer "Alice in Denver; Sunil in Boston" is the correct one.
23.
Which of the following statements about density is false?
Correct Answer
D. The density of most solids can be changed pretty easily