Mixtures and Solutions Review

Students are given a cup of warm saltwater. In order to determine how much salt is in the water, they -

• find the mass of the cup of saltwater

• filter the solution and find the mass of the salt

• estimate the amount of salt in the cup

• evaporate the water and find the mass of the salt

Students are given three beakers with 100 milliliters of water per beaker. They measure and record the temperature of each liquid. The students label the beakers Hot Water, Warm Water, and Cold Water. Students add one spoonful of instant tea to each beaker of water and record the amount of time it takes the tea to completely dissolve. Following the investigation, students are asked to draw a conclusion. Based on the information, which is a possible conclusion?

• The data shows that it takes the instant tea longest to dissolve in warm water.

• The results of the investigation prove hot water dissolves instant tea at a faster rate.

• The results of the investigation show instant tea only dissolves in hot water.

• The results show no distinct patterns observed during the investigation..

Tags

NGSS.MS-PS3-4

Which of the following describes a difference between the two substances pictured below?

• Water and salt is a solution and water and sand is a simple mixture.

• Water and salt is a simple mixture and sand and water is a solution.

• Both vases depict water in the beakers.

• Neither vase is a simple mixture.

Tags

NGSS.MS-PS1-2

Investigations should always be safe. Which safety equipment is NOT needed when working in a laboratory setting that requires a heat source?

• Safety goggles

• Tongs

• Gloves

• Notebook

A sample of ocean water is collected in a glass beaker. The sample is placed on a table. After 15 minutes, the sand settled to the bottom of the beaker. Which best explains why the salt did not settle to the bottom of the beaker?

• The salt evaporated when the sample of ocean water settled.

• The salt in the ocean water was dissolved in the sample.

• The salt floated on top of the ocean water sample.

• The salt settled to the bottom of the beaker but was hidden among the grains of sand.

Students write the following lab report.

1. Place two beakers of water on a hot plate and heat.

2. Remove the beakers from the hot plate using .

3. Mix instant coffee into Beaker 1.

4. Mix sand into Beaker 2.

5. Stir each mixture.

Conclusion:

The instant coffee dissolved, while the sand sank to the bottom of the beaker. The instant coffee and water are a and the sand and water are a mixture.

Which information completed the missing sections of the lab report?

• Lab coat, mixture

• Spatula, solution

• Safety goggles, mixture

• Protective gloves, solution

Which of the following is NOT a solution?

• Chocolate milk

• Oil and vinegar

• Salt and water

• Sugar water

A student mixes some dark gray iron filings with limestone, a type of powered rock. The mixture that results appears to be one light gray powder. What property allows for the easiest separation of this mixture?

• Density

• Color

• Mass

• Magnetism

Which of the following mixtures is the easiest to separate?

• Powdered drink mix, sugar, and water

• Sand and sugar

• Trail mix

• Oil and water

Which of the following is a solution?

• Rocks and sand

• Rocks and water

• Sugar and sand

• Sugar and water