STEM303 Pre-Test

In identifying a sample of a pure substance, which may be its chemical property?

• Its mass is 26.87g.

• It melts when heated.

• It burns in air.

• It is a good heat conductor.

All of the following are properties of antimony. Which one is NOT a physical property?

• It is one of the few substances that expands upon freezing.

• It has both yellow and gray forms (allotropes) in the solid state.

• It is a solid at room temperature.

• It burns in an atmosphere of chlorine.

It refers to atoms of the same element with different atomic mass but the same atomic number.

• ions

• ionic compound

• isotope

• isotopic symbol

If the number of protons is 19 and the number of neutrons is 20, which element from the periodic table is being referred to?

• K

• Ca

• Sc

• Ti

What is the correct name of the compound CrCl₃?

• monochromium trichloride

• chromium trichloride

• chromium chloride

• chromium (III) chloride

In the formula FeCl₃, what is the charge of the cation?

• -1

• +1

• +3

• -3

What is the formula for the compound that forms between lead (II) and chromate ion?

• PbCrO₄

• Pb₂(CrO₄)₂

• PbCr₂O₇

• PbCrO₃

Which of the following common laboratory operations/method would most efficiently separate insoluble solid from liquid?

• decantation

• evaporation

• filtration

• precipitation

How do you call this separation technique?

• sublimation

• evaporation

• distillation

• decantation

Sediment is the term for the substance that settles down in what physical process?

• filtration

• decantation

• precipitation

• evaporation