Measurements show that unknown compound X has the following composition: element mass % chromium 68.4% oxygen 31.5% Write the empirical chemical formula of X.

The empirical formula of X  is

Explanation:

If percentage are given then we are taking total mass is 100 grams.

So, the mass of each element is equal to the percentage given.

Mass of Cr = 68.4 g

Mass of O = 31.5 g

Step 1 : convert given masses into moles.

Moles of Cr =

Moles of O =

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For Cr =

For O =

The simple whole number ratio of Cr : O= 2: 3

Hence the empirical formula is

the answer

explanation:

the capillary tube was too close to the bottom of the beaker.

the ruler may have moved.

water got into the capillary tube.

the temperature was not allowed to equilibrate in the 2-4 minutes.