ACT Science 2.4 Research Summary Passage

ACT Science: Research Summary Passage Drill 2, Problem 4. What is a possible explanation for the observation?

ACT ScienceResearch Summary Passage
ChemistryProperties of Matter
Thermochemistry
LanguageEnglish Language
Product TypeACT Science
Scientific ProcessesCritique

Transcript

00:25

What is a possible explanation for this amazing phenomenon?

00:28

And here are the potential answers…

00:31

What’s this question asking?

00:32

Well, we have to figure out what mistakes the student made.

00:35

Awesome. We have plenty of experience making mistakes. Should be easy to recognize.

00:40

So… when was this student’s “Oh shoot” moment… the one that each of us has when

00:43

we realize we’ve locked ourselves out of the house?

00:47

Well, this student’s moment wasn’t quite so drastic…it was probably around the time

00:51

she saw that her filter paper had failed and none of the salt was left on the paper.

00:55

But why did this happen?

00:57

Well, if she had paid as much attention as we did while reading the procedure,

01:01

she would have seen the sentences:

01:03

“If the mixture contains a liquid, one technique is to pass the mixture over a filter.”

01:09

“This step will remove any components of a mixture that are not dissolved in the aqueous mixture.”

01:14

Hmm, this step will remove components that are NOT dissolved.

01:18

NOT dissolved, not dissolved…what’s the problem?

01:21

Oh yeah! Salt dissolves in water, which means the crystals can’t be separated

01:26

from each other with plain ol’ filter.

01:28

No, salt and water have a deeper connection than that…it’ll take a lot more to separate them…

01:32

A distillation chamber might do the trick, though.

01:35

So the filter paper separates sand and water, and the distillation chamber

01:39

separates salt and water.

01:41

The student didn’t do anything wrong.

01:42

Turns out her ‘oh shoot’ moment wasn’t even necessary.

01:45

Looks like A is the right answer.

01:47

Oh shoot…