Matter classification, solubility, gas laws practice

1.      An example of a mixture is

• salt (NaCl)

   

• NaCl dissolved in water

• liquid mercury (Hg)

• Water (H₂O)

  A student lights a candle and the wax begins to melt.  Which statement describes the movement of the particles as the solid candle melts to a liquid?

• The particles increase in energy and their intermolecular forces decrease.

• The particles increase in energy and their intermolecular forces increase.

• The particles decrease in energy and their intermolecular forces decrease. 

• The particles decrease in energy and their intermolecular forces increase.

1.      A student is investigating a substance to determine what it is made up of.  He studies the physical and chemical properties of the substance.

 

Which of these properties of the substance is a chemical property? 

• The melting point of the substance.

• The density of the substance.

• How easily the substance bends.

• How well the substance burns.

Which of the following pictures shows a compound at the molecular level?

• A

• B

• C

• none of these

1.        A solubility curve for KNO₃ is shown. According to the graph, what is the maximum approximate mass of KNO₃ that would dissolve at 60^OC and what is the relationship between temperature and solubility?

•      The mass is approximately 140g; increased temperatures lead to a decrease in solubility. 

• The mass is approximately 110g; increased temperatures lead to a decrease in solubility.

•   The mass is approximately 110g; increased temperatures lead to an increase in solubility.

• The mass is approximately 140g; increased temperatures lead to an increase in solubility.

A student wants to investigate the relationship between pressure and volume in nitrogen gas (N₂) by using a pressure sensor on an airtight 25-milliliter (mL) syringe as shown in the diagram.

 

In step 1 of the investigation, the student will add N₂ to the syringe at 20°C.

How should the student proceed with the investigation, and which graph shows what the student will MOST LIKELY observe?

• 
• 
• 
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A sample of Ne gas occupies 0.220L at 0.86 atm. What will be its volume at 0.288atm?

• 0.656 L

• 0.0737 L

• 1.13 L

• 5 L

What is the solubility of KCl at 25°C? 

• 35 g

• 9 g

• 40 g

• 92 g

A mass of 100 g of NaNO₃ is dissolved in 100 g of water at 80ºC. 

            a) Is the solution saturated, supersaturated, or unsaturated?

• saturated

• unsaturated

• supersaturated

Which section has the weakest intermolecular forces?

• a

• b

• c

• d

• e