Below Is a Diagram Representing a Solvent A(l)in a 1-L

question 38

Multiple Choice

Below is a diagram representing a solvent A(l) in a 1-L beaker,and a solute X dissolved in the solvent.Solvent A has a density of 0.8 g/mL,and a molar mass of 40 g/mol. Solute X has a molar mass of 30 g/mol.Each circle of X represents 1 mol of X.Assume that the solute addition does not significantly change the volume of liquid in the beaker. What is the mole fraction of the solute X in this solution?

• A)0.67
• B)0.53
• C)0.27
• D)0.21
• E)0.04

---

Definitions:

Melatonin

A hormone produced by the pineal gland in the brain, involved in regulating the sleep-wake cycle.

Non-rapid Eye Movement Sleep

A type of sleep that includes stages 1-3, characterized by a gradual decrease in heart rate, breathing rate, and muscle activity.

Startles Easily

A heightened response to sudden, unexpected stimuli, indicating increased sensitivity or anxiety.

Awaken

To rouse from sleep or to become alert and conscious after being asleep or less alert.