QUESTION: 561 Topic Exam C: Section 3 (science)

Lorna noticed that the amount of time needed to boil water was related to the shape of container she was using. She decided to measure the time necessary to bring 500 ml of water at room temperature to a boil on preheated hotplates. She used five cylindrical 500 milliliter Pyrex glass containers, each having the same wall thickness but a different base radius and height. In other words, some containers were narrow and long, others were wide and shallow. This is the table she prepared to record her data.

She placed each container containing the same amount of water on a hotplate, and placed a thermometer in each one to monitor the temperature. She noticed that the temperature was increasing faster in the containers with a larger radius. After some time, she observed boiling in the 10 cm radius container. She was about to record the time in the table she had set up, but noticed that there seemed to be less water in that container than she originally put in. She transferred the water into a graduated cylinder, and indeed found that the volume was below 300 ml. She proceeded with her experiment. The boiling in container 5 was followed by boiling in containers 4, 3, 2, and 1, in that order. Lorna checked the volume of the water in each container and found that it was lower than 300 ml. She also found that the decrease in volume was highest in the container with the largest radius. In container 1, volume decrease was barely detectable. While the decrease in volumes prevented her from getting meaningful data on boiling, they gave her an idea of how container shapes affect boiling times. In addition, she got an idea for her next project evaporation from containers of different shapes.

The decrease in water volume is most likely the result of:

malfunction in the hotplate.
evaporation.
a careless spill.
microorganisms.

Answer(s): B

Explanation:

There is no mention of problems associated with A, C, and D in the passage. The last sentence in the passage should point you to the correct answer.

Reveal Solution Next Question

QUESTION: 562 Topic Exam C: Section 3 (science)

Lorna noticed that the amount of time needed to boil water was related to the shape of container she was using. She decided to measure the time necessary to bring 500 ml of water at room temperature to a boil on preheated hotplates. She used five cylindrical 500 milliliter Pyrex glass containers, each having the same wall thickness but a different base radius and height. In other words, some containers were narrow and long, others were wide and shallow. This is the table she prepared to record her data.

She placed each container containing the same amount of water on a hotplate, and placed a thermometer in each one to monitor the temperature. She noticed that the temperature was increasing faster in the containers with a larger radius. After some time, she observed boiling in the 10 cm radius container. She was about to record the time in the table she had set up, but noticed that there seemed to be less water in that container than she originally put in. She transferred the water into a graduated cylinder, and indeed found that the volume was below 300 ml. She proceeded with her experiment. The boiling in container 5 was followed by boiling in containers 4, 3, 2, and 1, in that order. Lorna checked the volume of the water in each container and found that it was lower than 300 ml. She also found that the decrease in volume was highest in the container with the largest radius. In container 1, volume decrease was barely detectable. While the decrease in volumes prevented her from getting meaningful data on boiling, they gave her an idea of how container shapes affect boiling times. In addition, she got an idea for her next project evaporation from containers of different shapes.

What is a fair objection to Lorna's experimental setup?

The water she used was not distilled.
She didn't stir the water.
She used different hotplates for different containers.
She set up a data table before she performed the experiment.

Answer(s): C

Explanation:

This question required you to remember that it's important to keep the experimental conditions unchanged throughout the experiment. Different hotplates, just like different ovens, may differ in their heating efficiency and could affect the boiling times she was trying to measure. As long as all water used in the experiment came from the same source, it shouldn't matter whether it was distilled or not. Stirring is not necessary since there is nothing to mix. There is nothing wrong with setting up a data sheet before the experiment.

Reveal Solution Next Question

QUESTION: 563 Topic Exam C: Section 3 (science)

the rate of evaporation of water is higher from containers with a larger radius.
the rate of evaporation of water is lower from containers with a larger radius.
the rate of evaporation of water is the same from containers with a different radius, as long as the volume of water in the containers is the same.
the rate of evaporation can't be measured with the equipment Lorna used.

Answer(s): A

Explanation:

The statement that the volume change was greatest in the container with the largest radius and barely detectable in the container with the smallest radius should provide you with the right answer.

Reveal Solution Next Question

QUESTION: 564 Topic Exam C: Section 3 (science)

Lorna noticed that the amount of time needed to boil water was related to the shape of container she was using. She decided to measure the time necessary to bring 500 ml of water at room temperature to a boil on preheated hotplates. She used five cylindrical 500 milliliter Pyrex glass containers, each having the same wall thickness but a different base radius and height. In other words, some containers were narrow and long, others were wide and shallow. This is the table she prepared to record her data.

She placed each container containing the same amount of water on a hotplate, and placed a thermometer in each one to monitor the temperature. She noticed that the temperature was increasing faster in the containers with a larger radius. After some time, she observed boiling in the 10 cm radius container. She was about to record the time in the table she had set up, but noticed that there seemed to be less water in that container than she originally put in. She transferred the water into a graduated cylinder, and indeed found that the volume was below 300 ml. She proceeded with her experiment. The boiling in container 5 was followed by boiling in containers 4, 3, 2, and 1, in that order. Lorna checked the volume of the water in each container and found that it was lower than 300 ml. She also found that the decrease in volume was highest in the container with the largest radius. In container 1, volume decrease was barely detectable. While the decrease in volumes prevented her from getting meaningful data on boiling, they gave her an idea of how container shapes affect boiling times. In addition, she got an idea for her next project evaporation from containers of different shapes.

From the passage it can be inferred that a graduated cylinder is used:

by students only.
to measure how cylindrical a container is.
to measure the rate of evaporation of water.
to measure volumes.

Answer(s): D

Explanation:

The scientist used the graduate cylinder to check whether and by how much the volume in the container had changed.

Reveal Solution Next Question

Free ACT Test Exam Braindumps (page: 141)

QUESTION: 561 Topic Exam C: Section 3 (science)

Explanation:

QUESTION: 562 Topic Exam C: Section 3 (science)

Explanation:

QUESTION: 563 Topic Exam C: Section 3 (science)

Explanation:

QUESTION: 564 Topic Exam C: Section 3 (science)

Explanation: