Mixtures and Solutions Review

You mix 25 grams of salt into water and stir the solution until the salt dissolves. After the water evaporates, how much of your salt do you get back?

• 20 grams
• 25 grams
• 15 grams
• none

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which process would be best to use to separate a solution?

• freezing
• condensation
• evaporation
• melting

Tags

NGSS.MS-PS1-4

Which solids are soluble in water?

• iron filings and sand
• sand and salt
• salt and pepper
• lemonade powder and sugar

Tags

NGSS.MS-PS1-2

In which mixture do ALL the ingredients maintain their physical state?

• iron filings and sand

• pebbles, wood chips, leaves

• salt, hot water, sand

• sugar, hot water, salt

A student stirred four different substances into 4 different beakers and waited for the contents to settle. Based on the observations, which of the following substances did NOT dissolve in water?

• The particles settled to the bottom of the beaker.

• Clear: no visible particles.

• Particles collected on beaker walls above liquid.

• Particles formed a layer on top of water.

A mixture of beads was placed in a container. The beads are of various sizes, and each one is made of plastic, glass, or steal. The mixture would be easy to separate because all the beads ---

• are less dense than water

• are solids

• have the same mass

• are attracted to a magnet

A student reads the label on the bottle of salad dressing. The ingredients are: oil, vinegar, spices

The directions: shake well before using.

Why would the student shake the salad dressing before use?

• Vinegar and oil have different densities.

• Vinegar and oil both contain water.

• Vinegar and oil are both liquids

• Vinegar and oil easily for a solution.

A student added a powdered drink mix to water and the liquid turned red. The student decided the taste was too sweet and poured out half the liquid and added more water. What most likely happened when the water was added?

• The physical state changed.

• The red color became lighter.

• The liquid had a sweeter taste.

• The temperature of the liquid changed.

To separate a mixture of equal parts salt and pepper. If the salt and pepper grains are the same size, what should the student do to most easily separate the pepper from the salt?

• Use tweezers to remove each grain of pepper.

• Run a strong magnet through the mixture to attract the pepper.

• Use a strainer with a fine wire screen to remove the pepper.

• Stir the mixture with water then filter the pepper out of the water.

Objects such as foam cups, leaves and coins were left behind in a pool. Which explains a useful method for removing some of the objects?

• The coins and leaves are less dense than water, so they can be picked up off the bottom of the pool by divers.

• The foam cups have the same density as water, so they can be removed by the pool's filter.

• The foam cups are less dense than water, so they can be removed from the surface with a pool net.

• The foam cups, leaves and coins are less dense than water so they can all be removed from the surface with a pool net.