Argon is placed inside a container with a constant volume. The graph shows the estimated pressure y, in pounds per...

1. TRANSLATE what the question is asking

The question asks: "What is the estimated pressure of the argon, in psi, when the temperature is 600 kelvins?"

Let's break this down:

• Given: Temperature = 600 kelvins (this is our \(\mathrm{x}\)-value)
• Find: Pressure in psi (this is the \(\mathrm{y}\)-value we need to find)
• Method: Use the graph to find the corresponding pressure

2. VISUALIZE where to look on the graph

To find the pressure when temperature is 600 kelvins:

• Locate 600 on the x-axis (Temperature axis)
• Trace vertically upward from \(\mathrm{x = 600}\) until you hit the line
• From that point on the line, trace horizontally to the left to read the \(\mathrm{y}\)-value on the Pressure axis

3. Read the value from the graph

Following the process from Step 2:

• Starting at \(\mathrm{x = 600}\) on the horizontal axis
• Going up to the line
• Reading across to the y-axis

The line passes through the point \(\mathrm{(600, 12)}\).

This means when the temperature is 600 kelvins, the pressure is 12 psi.

Answer: B (12)

Why Students Usually Falter on This Problem

Most Common Error Path:

Weak TRANSLATE skill: Misidentifying which variable the question is asking for.

Students may read the question quickly and confuse what they need to find. The question gives them "600 kelvins" and asks for the pressure. Some students might:

• Read \(\mathrm{x = 600}\) and mistakenly report 600 as their answer (the temperature value itself)
• Look at a different \(\mathrm{x}\)-value, such as \(\mathrm{x = 300}\), and read \(\mathrm{y = 6}\)

These errors lead students to select Choice A (6) if they read the wrong point, or Choice D (600) if they report the given temperature instead of the requested pressure.

Second Most Common Error:

Poor VISUALIZE execution: Reading the graph scale incorrectly.

Students might struggle with:

• Misreading the gridlines on the y-axis
• Estimating incorrectly between gridlines
• Tracing to the wrong point on the line

This can cause confusion about which value corresponds to \(\mathrm{x = 600}\), potentially leading them to select Choice C (300) through scale misreading or calculation confusion.

The Bottom Line:

This problem tests whether students can accurately translate a word problem into a graph-reading task and then execute the mechanical skill of locating and reading coordinate values. The key challenge is maintaining clarity about what the question asks for (pressure, not temperature) and carefully reading the correct point on the graph.