Increasing the heat on an uncovered boiling pot of water does not increase the temperature of the water. What increases...

Sentence Structure

Sentence 1:

• Increasing the heat on an uncovered boiling pot of water
  • does not increase
    • the temperature of the water.
• What increases
  • is the rate
    • at which the water turns to vapor[?]

Sentence 2:

• [?] a pressure cooker pot, though,
• an airtight seal
  • traps the vapor in the pot,
    • creating pressure
      • that allows the temperature of the water to increase
        • past its boiling point.

Understanding the Meaning

Let's start reading from the beginning:

"Increasing the heat on an uncovered boiling pot of water does not increase the temperature of the water."

• This is telling us something interesting: when you turn up the heat on a pot of boiling water (without a lid), the water doesn't actually get hotter.

The sentence continues: "What increases is the rate at which the water turns to vapor"

• So what DOES happen when you increase the heat?
• The water evaporates faster - it turns to steam more quickly.
• But the temperature stays the same.

Now we've reached the blank: "vapor [?]"

Let's look at our choices:

• A: vapor. With (period, starting new sentence)
• B: vapor with (no punctuation)
• C: vapor, with (comma)
• D: vapor and with

To see what punctuation works here, let's read what comes next and understand what it's saying!

"With a pressure cooker pot, though, an airtight seal traps the vapor in the pot, creating pressure that allows the temperature of the water to increase past its boiling point."

Let me break down what this is telling us:

• "With a pressure cooker pot, though"
  • This signals we're now talking about a DIFFERENT scenario
  • "Though" tells us this will contrast with what we just learned
• "an airtight seal traps the vapor in the pot"
  • Unlike the uncovered pot where vapor escapes, here the lid keeps the steam inside
• "creating pressure that allows the temperature of the water to increase past its boiling point"
  • This trapped vapor creates pressure
  • This pressure actually DOES make the water hotter than its normal boiling point

So the complete picture shows us two contrasting scenarios:

• Uncovered pot → vapor escapes → temperature stays at boiling point
• Pressure cooker → vapor trapped → temperature goes ABOVE boiling point

Now, what do we notice about the structure here?

Let's check each part:

• First part: "What increases is the rate at which the water turns to vapor"
  • Has a subject: "What increases"
  • Has a verb: "is"
  • Expresses a complete thought that could stand alone as a sentence
• Second part: "an airtight seal traps the vapor in the pot..."
  • Has a subject: "an airtight seal"
  • Has a verb: "traps"
  • Expresses a complete thought that could stand alone as a sentence
  • (Yes, it starts with "With a pressure cooker pot, though" - but that's just setting the scene; the core sentence is still complete)

We have two independent, complete thoughts here. They're discussing two different scenarios that contrast with each other.

When you have two complete thoughts like this, you cannot just run them together or connect them with only a comma. They need proper separation.

The correct answer is A (vapor. With) - we need a period to create two separate sentences. This properly separates the two complete thoughts and makes the contrast between the two scenarios clear.

GRAMMAR CONCEPT APPLIED

Separating Independent Clauses (Complete Thoughts)

When you have two independent clauses - groups of words that each have their own subject and verb and express complete thoughts - you cannot join them inadequately. Each independent clause could stand alone as its own sentence.

Ways to properly handle two independent clauses:

1. Separate them with a period (two sentences):
   • Clause 1: "What increases is the rate at which the water turns to vapor."
   • Clause 2: "With a pressure cooker pot, though, an airtight seal traps the vapor."
   • Result: Two clear, separate sentences
2. Join them with a semicolon:
   • "The water evaporates faster; the temperature stays the same."
3. Join them with a comma + coordinating conjunction (these are called FANBOYS: for, and, nor, but, or, yet, so):
   • "The water evaporates faster, but the temperature stays the same."

What you CANNOT do:

Run them together with no punctuation: "What increases is the rate with a pressure cooker pot..." (run-on sentence)

Join them with only a comma: "What increases is the rate, with a pressure cooker pot..." (comma splice)

In this question: We have two independent clauses discussing contrasting scenarios. Choice A properly separates them with a period, creating two clear sentences that show the contrast between uncovered pots and pressure cookers.