Exam

Chapter 2 and 3

Lab 2.1

Experimental Errors- most errors lead to a decrease in mass

  • salt spills when you are pouring the salt from cap to bottle
  • not drying cap
  • clean pan between Mi and Mf
  • caps not tight-H20 spills out
  • not shaken long enough- salt not completely dissolved
  • bottle is wet on the outside

Lab 2.4

Condensation- comes from warm water vapor touching the cold surface of the bottle

  • changes the water vapor from a gas to a liquid

Experimental Errors

  • not wiping off the condensation on the outside
  • ice isnt fully melted
  • cap is not tight- evaporation

Lab 2.5 Mass of Copper and Sulfur

Experimental Errors

  • cap flame before reaction ends
  • shake test tube
  • hole in the rubber sheet (decrease in mass)

Lab 2.6 Mass of a Gas

Experimental Errors

  • cap not on tight or fast enough- lose in mass
  • bottle wet on outside during Mi
  • cap wet

Alka-seltzer

  • sodium bicarbonate--> baking soda releases a gas
  • cytric acid

Conservation of mass-in a closed system mass will remain constant, regardless of the actions of the processes inside the closed system

Lab 3.2 (Aluminum and Brass Cylinders)

Experimental Errors

  • cylinder is wet when it is being massed
  • remass same cylinder
  • H20 splashed out of graduated cylinder (decrease)

Mass and Volume Notes

  • objects that are made of the same substnace that have the same, volume, will have the same mass (regardless of their shape)

Funtion Graphs

Whatever comes after fuction of, goes on the x-axis

3.5 2 Cubes, Slab, and Rock Densities

The Rock

  • all have different densities becuase the Rock is formed by many substances being compressed together

Experimental Errors

  • measure volume of rock before measuring the mass-->increase in mass/density
  • measure from the end of the ruler instead of starting at the zero-->volume lower, increase density

Lab 3.6

Experimental Errors

  • liquids sticks to inside walls of cylinder--> mass increase, density increase
  • contaminated cylinder (wet on inside)

Magnesium sulfate= can be used as a laxitive, can be used as Epsom Salt-->the liquid w/higher density (A) had more

3.7 Density of a Gas

D= change off mass/change of volume

Experimental Errors

  • hand does not seal bottle (Volume increase=D decrease)
  • remove stopped before tubing (V increase= D decrease)
  • tubing then tablet then stopper (order) (Volume increase=D decrease)
  • forget to include foil in Mf (Mass increase=D increase)
  • stopper is not tight/hole in tubing/too long for tubing in bottle (volume increase= D decrease)
  • touch tablet after Mi (M increase= D increase)

Gas

  • from sodium bicarbonate in alka-seltzer
  • gas is carbon dioxide

1 meter= 100 cm