OPEN AND CLOSED SYSTEMS

It’s more than matter!

As you know, THE LAW OF CONSERVATION OF MASS STATES that during a chemical reaction, matter is not created or destroyed.

• This means that in a chemical reaction, all of the atoms present at the start of the reaction are present at the end of the reaction.

The Chemistry of Burnt Wood

• We know that the mass of the reactants must equal the mass of the products……But where does mass of the burnt wood go?

Literally, up in smoke

• It would be nearly impossible to measure all the matter involved in this reaction as so much escapes into the air.

This type of natural condition where different types of matter interact

freely with other matter is called an OPEN SYSTEM.

• The rusting of metal and the human body are both examples of open systems.

Keep this in mind!• SYSTEMS can include more than chemical

reactions. Cycles, energy and living and nonliving things can be described as systems.

If you want to measure ALL the matter occurring in a reaction you have to contain it!

Botulism in canned Closed system reaction. food.

In a CLOSED SYSTEM, matter does not enter or leave.

Terrarium Aqua Terrarium

In nature there are many more examples of Open Systems!

• Open or closed? Why?

• Open or closed? Why?•

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Open or Closed Systems?

In nature are there more open or closed systems? Why?

In a scientific experiment, which type of system would be the best to demonstrate conservation of mass? Why?