A Flask Containing Helium Gas Is Connected to an Open-Ended

question 12

Multiple Choice

A flask containing helium gas is connected to an open-ended mercury manometer. The open end is exposed to the atmosphere, where the prevailing pressure is 752 torr. The mercury level in the open arm is 26 mm above that in the arm connected to the flask of helium. What is the helium pressure, in torr?

• A) -26 torr
• B) 26 torr
• C) 726 torr
• D) 778 torr
• E) None of these choices is correct.

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Definitions:

Algae

An informal group of unicellular, or simple multicellular, photosynthetic protists that are important producers in aquatic ecosystems.

Thylakoid Membranes

Membrane-bound compartments inside chloroplasts and cyanobacteria where photosynthesis takes place.

ATP

Adenosine triphosphate, a molecule that stores and transfers energy within cells.

Noncyclic Electron Transport

A pathway in photosynthesis where electrons flow linearly from water to NADP+, producing oxygen and NADPH.