amount of substances

Question 1

define empirical formula

Answer 1

An empirical formula is the simplest ratio of atoms of each element in the compound.

Answer 2

Divide each mass (or % mass) by the atomic mass of the element

Step 2 : For each of the answers from step 1 divide by the smallest one of those
numbers.
Step 3: sometimes the numbers calculated in step 2 will need to be multiplied up to
give whole number

Answer 3

Weigh the sample bottle containing the required mass of solid
on a 2 dp balance
* Transfer to beaker and reweigh sample bottle
* Record the difference in mass
* Add 100cm3 of distilled water to the beaker. Use a glass rod to
stir to help dissolve the solid.
*Sometimes the substance may not dissolve well in cold water so
the beaker and its contents could be heated gently until all the
solid had dissolved.
* Pour solution into a 250cm3 graduated flask via a funnel. * Rinse beaker and funnel and add washings from the beaker
and glass rod to the volumetric flask. * Make up to the mark with distilled water using a dropping
pipette for last few drops. * Invert flask several times to ensure uniform solution.