What is the formula for a hydrate?

Answer 1

CALCULATING MASS OF WATER LOST IN HYDRATE

To calculate how much water was lost after a hydrate's been heated, subtract the mass of the anhydrate (after) from the mass of the hydrate (before).

Mass Hydrate - Mass Anhydrate = Mass Water Lost

EXPERIMENTAL VALUE PERCENT WATER IN HYDRATE

To calculate the experimental percent of water in a hydrate (using values gathered during the experiment), calculate how much water was lost (see "CALCULATING MASS OF WATER LOST" above). Do this by dividing the mass of the water lost (g) by the mass of the hydrate. Multiply the result by 100%.

mass water lost

- mass hydrate x 100%

THEORETICAL VALUE PERCENT WATER IN HYDRATE

To calculate the theoretical percent of water in a hydrate (using molar masses of substances rather than actual masses from experimental data), divide the molar mass of the water molecules by the molar mass of the hydrate; multiply the result by 100%.

- Molar mass water

Molar mass hydrate x 100%

Finding Molar Mass

# atoms element A * Atomic Mass element A = Mass A

# atoms element B * atomic mass element B = Mass B

... etc.

Add up all the mass values and you have the molar mass. Do this for both the anhydrate and water. For water's molar mass, you can also multiply 18.02 by the number of water molecules there are. This is a useful number to remember in order to save time test day and while doing homework practice problems too.

To find the molar mass of the hydrate, add the molar mass values for water and the anhydrate.

Molar Mass Water Molecules + Molar Mass Anhydrate = Molar Mass Hydrate

PERCENT ERROR WATER IN HYDRATE

In order to determine the percent error of the water in a hydrate, subtract the experimental value (what you determined using values found via experimentation) from the theoretical value (what is determined using molar masses), then divide value by the theoretical value; multiply result by 100%.

Theoretical Value - Experimental Value x 100%

----------- Theoretical Value

EMPIRICAL FORMULA OF HYDRATES(looking for quantity of water molecules)

In order to find how many water molecules there are within a hydration (finding the empirical formula for hydrate), follow the steps below according to what is given.

1. Calculate percent water in substance.

Divide the mass of water by the mass of the hydrate (before heating).

- mass water*

mass hydrate

* see "CALCULATING MASS OF WATER LOST IN HYDRATE" above. Sometimes this number is already given. If it is, then proceed to the next step.

2. Convert Mass to Moles.

Divide the mass of substance by its molar mass.

--------- Mass substance (g)

Molar mass substance (g/mol) = mol

Conversion Factor

mass substance (g) x 1 mol substance

----------------- atomic mass substance (g) = mol substance

Do this for both the anhydrate and water.

3. Find Mole Ratio; Multiply the number of moles until they are a whole number.

Find the mole ratio by dividing the number of moles for each substance by the smallest number of moles within the compound.

------- # mol anhydrate

smallest # moles compound

--------- # mol water

smallest # moles compound

AND/OR

-- mol H2O

mol hydrate = mol H2O per mol anhydrate

Multiply or are within <0.1 from being a whole number (then just round up). This is not necessary if all the moles values are already whole numbers or are within <0.1 from being whole numbers. Whatever value is used to get a non-round number to become a round number must also be the SAME number used to multiply the round mole value(s).

If you enjoy algebra, you can also do the following (solving for x):

18.02x/(18.02x + mass anhydrate) = % mass by water

where x = number of water molecules.

Answer 2

Hi my name is anyae and I'm 12.First, you have to measure the amount of mass of earth which is 300,000,000 billion kilometers of matter. Second, you have to multiply it by 2 and u get 600,000,000 acres of mass. Lastly you have to subtract 423,876,178 which is the speed of light from 600,000,000 to get your hydrate. !:-)!

Answer 3

Formula: X.nH2O

Where is is the main compound and n is a natural number

Answer 4

The formula for a hydrate is written as ionic compound + xH2O, where x represents the number of water molecules attached to each formula unit of the compound.

Answer 5

Anhydrate * X H2O

Answer 6

H2o

Answer 7

H2