Chemistry Things to Remember

Density

Mass/Volume

Mass

Density x Volume

Volume

Mass/Density

Temperature

The average kinetic energy of the individual particles

Percent Error Calculation

Measured value-Actual value/Actual value x 100

The most metallic elements are located in the...

Bottom Left

Most non-metallic elements are located in the...

Top Right

When reading scales...

Record all certain digits then estimate one uncertain digit further (beyond scale available)

To determine sig-figs if there is a decimal present...

Start at the left and count till you encounter a non-zero number, then that number and everything to the right of it is significant.

To determine sig-figs if there is not a decimal present...

Start at the right and count till you see a non-zero number, then that number and everything to the left of it is significant.

When working with acids and water...

Add the acid slowly to the water while stirring constantly.

Elements and compounds are...

Substances

Intensive physical properties

Independent of the amount of substance present ex: density, color, and melting point

Extensive physical properties

Dependent upon the amount of substance present ex: mass, volume, and length

Elements cannot be...

Decomposed into simpler substances

Compounds are usually broken down by...

Chemical Changes

The process of ascending a heating curve is...

Endothermic

Going down a heating curve is...

Exothermic

Exothermic reactions always...

Release heat

Endothermic reactions always...

Gain heat

Heat always flows from...

A higher temperature to a lower temperature

The # of joules per gram required to melt ice at its melting point is called...

Heat of Fusion

Heat of Fusion for Water....

334 J/G

Heat of Vaporization for Water...

2260 J/G

When asked to find the # of joules needed to change x grams of water to ice...

Multiply x grams by 334 J/G

Deposition

Gas?Solid

A mixture of ice and water is in equilibrium at STP, the temperature is...

0�C

The Conditions of pressure and temperature that exist when ice melts at its normal melting point are...

1 atm and 0�C

As a 1 gram sample of H2O(L) changes to H2O (G) the potential energy...

Increases

As a 1 gram sample of H2O(G) to H2O(L) the potential energy...

Decreases

C+273=

K

K-273=

C