Electrolytes and Concentration

When the ends of two wires, from a circuit containing a battery and a lightbulb, are placed into a beaker containing an aqueous solution the light bulb glows brightly. From this observation, you can conclude the solution is probably —

• a weak base

• a strong acid

• a pH neutral sample of a polar compound

• an acid added to a base

Tags

NGSS.HS-PS2-5

Which of the following describes a solution containing an electrolyte?

• The solute particles are so firmly bonded that they do not

  break apart.

• The solute particles permit the passage of an electric current.

• It is unstable, and all the solute will precipitate if the solution

  is disturbed.

• It cannot contain any more solute particles

Tags

NGSS.HS-PS2-5

Which of the following containers most likely contains sugar?

A B

• Container A because it forms ions.

• Container B because it forms ions.

• Container A because it does not form ions.

• Container B because it does not form ions.

Which of the following is a strong electrolyte when dissolved in water?

• NaNO₃

• C₂H₅OH

• C₁₂H₂₂O₁₁

• CH₄

Which of the following actions is most likely to speed up dissolution?

• Crystals of sodium carbonate (Na2CO3) are crushed into a powder before being added to the solvent.

• Water is cooled to 15°C before the solute is added.

• An aqueous solution of sodium chloride (NaCl) is placed in a pressurized container.

• Lithium iodide (LiI) is added to water and left to sit without stirring.

Tags

NGSS.MS-PS3-4

60g KNO₃ in 100 g of water at 80 º C is

• saturated

• unsaturated

• supersaturated

• none of the above

Tags

NGSS.HS-ESS2-5

NGSS.HS-PS1-5

All of these can affect the rate at which a solid dissolves in water except…

• a. Stirring the water

• b. Decreasing air pressure

• c. Increasing the temperature of the water

• d. Using larger crystals of the solid

Four chemical solutions are shown above. Which of the following solutions would correspond to a weak electrolyte?

• IV

• III

• II

• I and II

A chemist drops a few grams of solute into an unknown solution. No crystals form and the solute does not dissolve. This solution would be considered…

• a. Unsaturated

• b. Saturated

• c. Supersaturated

• d. None of the above

Which substance makes an unsaturated solution at a temperature of 40 °C ?

• 40 g NaCl

• 40 g KCl

• 40 g KNO3

• 50 g K₂Cr₂O₇