Oxygen gas is placed inside a tank with a constant volume. The graph shows the estimated temperature y, in kelvins,...

1. TRANSLATE the graph axes and question

Given information from the graph:

• x-axis (horizontal): Pressure in atmospheres
• y-axis (vertical): Temperature in kelvins
• A straight line showing the relationship between pressure and temperature

What the question asks:

"What is the estimated temperature when pressure is 6 atmospheres?"

TRANSLATE this into graph reading language:

• Find the point on the line where \(\mathrm{x = 6}\)
• Report the y-coordinate of that point

2. VISUALIZE the process of reading the graph

Locate the x-value:

• Find 6 on the horizontal axis (pressure)
• This is between 5 and 7 on the x-axis

Trace to the line:

• Move vertically upward from \(\mathrm{x = 6}\) until you hit the line
• This intersects the line at a specific point

Read the y-value:

• From the intersection point, trace horizontally to the y-axis
• Read the temperature value on the vertical scale
• The point appears to be at \(\mathrm{y = 700}\) kelvins

3. Select the answer

The y-coordinate when \(\mathrm{x = 6}\) is approximately 700.

Answer: C. 700

Why Students Usually Falter on This Problem

Most Common Error Path:

Weak TRANSLATE skill: Students misunderstand what value they're supposed to find. They see "when pressure is 6 atmospheres" and think the answer is 6, confusing the input value (\(\mathrm{x = 6}\)) with the output value (\(\mathrm{y = ?}\)).

What goes wrong: They read the question as asking "what is the pressure?" instead of "what is the temperature at that pressure?" Since the question explicitly states \(\mathrm{pressure = 6}\) atmospheres, they select that value.

This leads them to select Choice A (6).

Second Most Common Error:

Poor VISUALIZE execution: Students misread the y-axis scale or incorrectly trace from \(\mathrm{x = 6}\) to the line. The gridlines show intervals of 100 kelvins, and students might:

• Land between gridlines and round incorrectly
• Miscount the gridlines
• Read a nearby value instead of the correct one

This causes them to select Choice B (60) or Choice D (760) depending on their reading error.

The Bottom Line:

This problem tests whether students can translate a word question into a graph-reading task and correctly identify which coordinate (x or y) answers the question. The key is recognizing that "when pressure is 6" gives you the x-value, and you need to find the corresponding y-value (temperature).