Observations & Chemical Changes Lab Quiz

What is the correct term for a solid forming in a reaction solution?

• Effervescence

• Precipitate

• Filtrate

• Solute

Describe the physical properties of copper metal before the reaction. Include at least three characteristics.

What is the name of the toxic brown gas produced when copper reacts with nitric acid?

When sodium hydroxide is added to the solution, a new blue solid appears. What is this compound?

• Copper(II) sulfate

• Copper(II) oxide

• Copper(II) hydroxide

• Copper(II) nitrate

When heating the copper(II) hydroxide, it turns black. What compound is responsible for this color change?

Match the following separation techniques with their descriptions.

Why is decanting used in this experiment?

• To remove excess zinc metal

• To separate solid copper from liquid waste

• To dissolve copper into solution

• To measure the volume of the acid added

If the solid copper was lost during decanting, what type of error would this introduce? Explain.

What does heating to a constant mass ensure?

• That the reaction is complete

• That all the nitric acid is used up

• That the copper has fully dried before measuring

• That gas is produced during the reaction

If the copper is still wet when weighed at the end, how does this affect the mass measurement?