Exploring Mixtures and Solutions

A mixture of iron filings and sand is placed in a container. Describe a method to separate the iron filings from the sand and explain why this method works.

• Use a magnet to attract the iron filings because they are magnetic, while sand is not.

• Add water to dissolve the sand and leave the iron filings behind.

• Heat the mixture to melt the iron filings, leaving the sand behind.

• Use a sieve to separate the iron filings from the sand based on size.

You have a mixture of sand and water. Describe a process to separate the sand from the water and explain the reasoning behind your choice.

• Use a filter to separate the sand from the water because the sand particles are larger and will be trapped by the filter.

• Use a magnet to attract the sand particles out of the water.

• Boil the water to evaporate it, leaving the sand behind.

• Use a centrifuge to spin the mixture and separate the sand from the water.

Compare the properties of salt and water before and after they are combined into a solution. What evidence supports the conservation of matter in this process?

• The mass of the solution is less than the sum of the masses of salt and water.

• The mass of the solution is equal to the sum of the masses of salt and water, demonstrating conservation of matter.

• The salt disappears completely, indicating a loss of matter.

• The water evaporates, leaving only salt behind.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A student mixes sugar and water to create a solution. How can the student demonstrate that the sugar is still present in the solution even though it is not visible?

• By tasting the solution to detect the sweetness of the sugar.

• By observing the color change in the solution.

• By using a magnet to attract the sugar particles.

• By filtering the solution to separate the sugar from the water.

Tags

NGSS.MS-PS1-2

Explain how you can demonstrate that a mixture of oil and water maintains the physical properties of its substances.

• By shaking the mixture and observing that the oil and water do not mix.

• By heating the mixture until the oil dissolves in the water.

• By using a magnet to separate the oil from the water.

• By filtering the mixture to separate the oil from the water.

Tags

NGSS.MS-PS1-2

A student combines vinegar and baking soda in a closed container. How can the student demonstrate that matter is conserved during this chemical reaction?

• By measuring the mass of the container and its contents before and after the reaction.

• By observing the production of gas bubbles.

• By noting the temperature change during the reaction.

• By observing the color change in the mixture.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Describe a method to separate a mixture of sand and salt and explain the reasoning behind your choice.

• Add water to dissolve the salt, then filter the mixture to separate the sand, and finally evaporate the water to recover the salt.

• Use a magnet to attract the salt particles.

• Heat the mixture to melt the sand, leaving the salt behind.

• Use a sieve to separate the sand from the salt based on size.

How can you demonstrate that a solution of sugar and water maintains the physical properties of its substances?

• By observing that the sugar crystals are visible in the solution.

• By tasting the solution to detect the sweetness of the sugar.

• By using a magnet to separate the sugar from the water.

• By filtering the solution to separate the sugar from the water.

Tags

NGSS.MS-PS1-2

A student mixes sand and iron filings. How can the student demonstrate that the mixture maintains the physical properties of its substances?

• By using a magnet to separate the iron filings from the sand.

• By dissolving the mixture in water.

• By heating the mixture to melt the iron filings.

• By observing a color change in the mixture.

Explain how you can demonstrate that a solution of salt and water conserves matter.

• By measuring the mass of the solution before and after dissolving the salt.

• By observing the salt crystals in the solution.

• By using a magnet to separate the salt from the water.

• By filtering the solution to separate the salt from the water.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5