Unit conversion check:\nOne bar (1 bar) is approximately equal to how many atmospheres?

Introduction / Context:
Engineering pressures may be quoted in bar or atmospheres. A quick conversion is essential for sanity checks and calculations. One atmosphere is 1.01325 bar, so 1 bar is about 0.987 atm—“approximately 1” for most practical problems.

Given Data / Assumptions:

• 1 atm = 101.325 kPa; 1 bar = 100 kPa.
• Approximation acceptable for the question’s intent.

Concept / Approach:
Compute the ratio atm/bar or bar/atm: 1 bar / 1 atm = 100 / 101.325 ≈ 0.987, which is essentially 1 to two significant figures. Therefore, selecting “1” is the intended approximate equality.

Step-by-Step Solution:
Use kPa definitions.Take ratio: 100 / 101.325 ≈ 0.987.Therefore, 1 bar ≈ 1 atm (approx).

Verification / Alternative check:
Converting common pressures (e.g., 5 bar ≈ 4.93 atm) confirms the near-equality.

Why Other Options Are Wrong:
10, 100, 1000 are orders of magnitude off; 0.1 would correspond to 0.1 atm, not 1 bar.

Common Pitfalls:
Confusing bar with mbar (millibar) or atm with “at” (technical atmosphere) in older literature.

Final Answer:
1