Chemistry A - Unit 1 - Properties and Changes of Matter

Calculate the density of the substance. A sample of a substance has a mass of 4.2 grams and a volume of 6 milliliters. The density of this substance is ( ) grams/milliliter.

0.7

In an experiment, Lydia added 50 grams of sugar to 200 milliliters of water. She stirred the mixture, and the sugar eventually dissolved into the water and couldn't be seen. The volume of the solution increased, but there was no noticeable change in color, odor, or temperature. Which statement best describes what happened in Lydia's experiment?

A physical change took place during this experiment.

Marcus measured the masses and volumes of samples of four different substances, and he calculated their densities. The table shows Marcus's measured and calculated values. What is the unknown sample made of?

titanium

A student places a sample of white sodium bicarbonate powder in a test tube and heats it. The student observes that the sodium bicarbonate undergoes a chemical change. After the change, what must be true about the substance in the test tube?

It is not sodium bicarbonate.

A student makes several observations about a piece of iron. Which observation describes a chemical property of the iron?

It rusts when exposed to air.

Which type of property can be observed only by changing a substance into a different substance?

chemical property

A 46.9 gram sample of a substance has a volume of about 3.5 centimeters3. It is solid at a room temperature of 23ºC. Out of the four substances whose properties are given, which is the most likely identity of this substance?

hafnium

A scientist carried out several different procedures, each of which caused a change in matter. Select each procedure that is likely a chemical change.

1. Bubbles were produced when iron was placed in acid. 2. Two liquids were combined, and a solid appeared. 3. A white substance turned blue when water was added.

Classify the properties as intensive or extensive.

Intensive: density, color, freezing point Extensive: mass, volume

Which type of change does the statement describe?

Physical: There is no change...,Particles retain their composition... Chemical: Particles rearrange...,The chemical properties of the substance change.