5-1, 5-2 Observing Chemical Reactions & Writing Chemical Equations

22 terms by acarlino

Create a new folder

Advertisement Upgrade to remove ads

evidence of chemical reactions, writing equations

2 main types of evidence of a chemical reaction...

change in properties and change in energy

changes in properties include...

precipitation, gas production, and color change

changes in energy include...

endothermic reactions & exothermic reactions

precipitate

a solid that forms from 2 solutions mixing

One observable characteristic of a chemical reaction is

the production of new materials that have properties different than those of the starting materials

color change

like leaves changing color in the fall

gas production

like oxygen bubbles forming during photosynthesis

endothermic reaction

energy is absorbed, substance feels cooler

exothermic reaction

energy is released as heat, substance feels warmer

The second observable characteristic of a chemical reaction is

a change in energy

Chemical reactions occur when

chemical bonds break, or new bonds form

chemical equations are

a shorter, easier way to show chemical reactions using symbols instead of words

Formulas identify

the elements in the compound and the ratio of atoms that make up a substance

The subscript tells you

the number of atoms of an element in a molecule

If a letter symbol in a chemical formula doesn't have a subscript

the number 1 is understood

A chemical equation tells you

the substances you start with and the substances you get at the end

reactants

the materials you have at the beginning

products

the different materials you have when the reaction is complete

A chemical equation uses formulas & symbols to

show the reactants and products of a chemical reaction

Conservation of Mass 1

the amount of matter involved in a chemical reaction does not change

Conservation of Mass 2

the total mass of the reactants must equal the total mass of the products

Conservation of Mass 3

during a chemical reaction, matter is not created or destroyed

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set