926 G of an Unknown Solid Is Dissolved in a Coffee

question 14

Multiple Choice

9.26 g of an unknown solid is dissolved in a coffee cup calorimeter that contains 62.0 mL of water. The measured temperature increased from 23.4 °C to 24.7 °C. The specific heat of water is 4.184 J g^-1 °C^-1, and assume the density of the solution is 1.00 g mL^-1. Calculate the molecular weight of the unknown solid if the Δ_rH was determined to be -2.51 kJ mol^-1 via another experiment.

• A)69 g mol^-1
• B)48 g mol^-1
• C)76 g mol^-1
• D)184 g mol^-1
• E)93 g mol^-1

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Definitions:

Myogenic Mechanism

A physiological mechanism by which blood vessels automatically adjust their resistance to maintain constant blood flow despite changes in arterial blood pressure.

Afferent Arterioles

Small blood vessels that carry blood toward the nephrons in the kidneys, regulating blood pressure and filtration.

Blood Pressure

The force exerted by circulating blood on the walls of blood vessels, an essential indicator of cardiovascular health.

Proximal Convoluted Tubule

A segment of the nephron in the kidney where the bulk of reabsorption of water, ions, and nutrients from the filtered blood occurs.