2.1 Practice Questions (Unit 2)

The diagram represents a gaseous sample of matter in a sealed container. Each circle of a different shade represents a different type of atom. Which of the following best describes the particle diagram?

• It represents three different compounds mixed together with one element.

• It represents one compound mixed together with three different elements.

• It represents four different elements, and no compounds are represented.

• It represents a single compound composed of three elements.

Tags

NGSS.MS-PS1-1

During a demonstration, a teacher makes a mixture by combining 40mL of methanol and 60mL of water, as shown. The teacher asks students to describe what happens so that they can create a model together.

Based on the particle diagram, what will be observed?

• Methanol and water molecules will form two layers with methanol on the top.

• Methanol and water molecules will form two layers with methanol on the bottom.

• Methanol and water molecules will not form layers.

• The methanol and water molecules will combine to form a new substance.

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

Consider the models are shown. Check the word that best describes each model to the corresponding box.

• Atom

• Molecule

• Compound

• Mixture

Tags

NGSS.MS-PS1-1

A student claims that intermolecular forces are overcome when water boils, but intramolecular forces are not. Which of the following particle diagrams can be used to support the claim?

• 
• 
• 
• 

Tags

NGSS.HS-PS3-4

A solution is made by dissolving solid sucrose in water. The solution is heated gently until all of the water evaporates. The following data are collected.

Which of the following can be concluded from the results of the experiment?

• Some sucrose vaporized when the sample was heated.

• Covalent bonds in the sucrose were broken during the experiment.

• The solution contained more sucrose than water, by mass.

• The solution contained

Tags

NGSS.HS-PS3-4

A chemist uses distillation to remove some methanol from a mixture of equal parts methanol and water. The chemist heats the mixture and collects some of the first gas produced. A representative sample of the liquid and gas are shown in the particulate views.

Which of the following explains the composition of the gas?

• The covalent bonds in methanol are weaker than those in water, so methanol has a lower boiling point than water has.

• The covalent bonds in methanol are stronger than those in water, so methanol has a higher boiling point than water has.

• The intermolecular forces between methanol molecules are weaker than those between water molecules, so methanol has a lower boiling point than water has.

• The intermolecular forces between methanol molecules are stronger than those between water molecules, so methanol has a higher boiling point than water has.

A chemist uses distillation to remove some methanol from a mixture of equal parts methanol and water. The chemist heats the mixture and collects some of the first gas produced. A representative sample of the liquid and gas are shown in the particulate views.

If the total pressure of the gas sample is

1.0atm, the partial pressure of H₂O(g) in the gas sample produced is predicted to be closest to which of the following?

• 0.10atm

• 0.50atm

• 0.90atm

• 1.0atm