###### Asked in Hair Loss and TreatmentChemistryDefinitionsComparisons

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# What is an anhydrate?

## Answer

###### Wiki User

###### October 17, 2014 12:33AM

A chemical compound formed from another, often an acid, by the removal of water.

## Related Questions

###### Asked in Chemistry

### What is a anhydrate?

###### Asked in Chemistry

### Reaction when the anhydrous salt samples were treated with the liquid?

Usually, when a salt anhydrate is treated with water, its
crystalline structure will reappear. Many solids are crystalline
when the water of hydration, or water of crystallization is
present. If you vaporize this away with heat, the crystalline
structure collapses and you are usually left with a powdery
anhydrate. Add water and it re-crystallizes. Be careful though:
adding the water back will also release the heat you put into it to
remove it. So adding the water is an exothermic process.

###### Asked in Math and Arithmetic, Chemistry, Percentages, Fractions, and Decimal Values, How To

### How to find the percent of water in a hydrate?

1. Find the molar mass of the hydrate.
Find the molar mass of the water molecules (18.01528 x # water
molecules) and of the anhydrate; add the values together to find
the molar mass of the hydrate.
Molar Mass Water + Molar Mass Anhydrate = Molar Mass Hydrate
2. Find the percent of water in hydrate.
Divide the molar mass of water by the molar mass of hydrate;
multiply by 100%.
- Mass water
Mass hydrate x 100%

###### Asked in Elements and Compounds, Chemical Bonding

### What are hydrates and what is hydration?

Some salts have a property called "hygroscopy". This means that
they absorb water from the air in a preset ratio (like, 5 molecules
of water for every 2 units of the salt for example). They give this
water off when heated. Therefore, there are actually two forms of
the salt, they "hydrate" or "hydrous" form, which has the water,
and the "anhydrate" or "anhydrous form", which does not. These two
forms can have surprisingly different properties. Hydration is the
process of going from an anhydrate to a hydrate (the source of the
water doesn't matter, so don't say it's "absorbing water from the
air").

###### Asked in Math and Arithmetic, Chemistry, Percentages, Fractions, and Decimal Values

### How do you calculate percent water lost in hydrate?

1. Find the amount of water lost.
Subtract the mass of the anhydrate (substance after it's
been heated [meaning no water left]) from the mass of the
hydrate (substance before it's been heated [meaning water is
present]).
Water lost = mass hydrate - mass anhydrate (mass
before - mass after).
2. Find the percent water lost in hydrate.
Divide the amount of water lost by the mass of the hydrate;
multiply result by 100%.
- water lost
mass hydrate x 100%

###### Asked in Chemistry

### What is the theoretical percentage of water of hydration in cacl2-2h20?

1. Find the molar mass of the hydrate (Calcium Chloride
Dihydrate).
Find the molar mass of water and the anhydrate (anhydrate +
water = hydrate); add the molar mass values of each to find the
molar mass of the hydrate.
Molar Mass CaCl2: 110.98g
+ Molar Mass H2O: 36.04g*
Molar Mass CaCl2 * 2H2O: 147.01g
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 value for molar
mass. Do this for both the anhydrate and the water molecules. Add
these values together to find the molar mass of the hydrate.
Molar Mass Anhydrate + Molar Mass Water Molecules* = Molar Mass
Hydrate
* Tip: the molar mass of water for all hydrate
calculations is 18.02g x number of water molecules.
This number may be useful to remember on the day of the test or
while doing practice problems.*
2. Calculate the percentage of water in hydrate.
Divide the molar mass of water by the molar mass of the hydrate,
and multiply result by 100%.
36.04g
147.01g x 100%
Percent water in hydrate is 24.52%.

###### Asked in Chemistry

### A 6.88 g sample of the hydrated crystal Rb2CO3 xH2O is heated until all the water is removed The remaining solid weighs 5.24 g Calculate the formula of the hydrated crystal?

Okay, the anhydrate that weighs 5.24g (after heating) is pure
rubidium carbonate (Rb2CO3) so the 6.88g represents the molar mass
of the hydrated crystal. Set up an algebraic direct proportion:
6.88/x = 5.24/(molar mass of Rb2CO3) which is 231g/mol. Solve for x
to get 303.3. Subtract out the anhydrate mass: 303.3 - 231 = 72.3.
Now divide that number by water's molar mass, which is 18g/mol:
72.3/18 = 4, so the formula of the hydrate crystal is
Rb2CO3-4H2O.

###### Asked in Math and Arithmetic, Chemistry, Percentages, Fractions, and Decimal Values

### Calculate The percent Water In CoC2H3O22 x 4H2O?

1. Find the molar mass (MM) of the hydrate (cobalt acetate
tetrahydrate).
MM Co(C2H3O2)2: 177.02g (anhydrate)
+ MM 4H2O: 72.06g (water)
MM Co(C2H3O2)2 * 4H2O = 249.08g (hydrate)
2. Find the percent water of hydrate. Divide the mass of
water by the mass of hydrate (anhydrate + water = hydrate).
72.06g
249.08g x 100%
Percent water of hydrate is 28.93%.
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 of the mass values and you have the molar mass of the
substance.

###### Asked in Chemistry

### How do you calculate hydrates?

It's not too hard: take a sample of a hydrate and get a really
accurate mass for it. Then, stick your sample in a test tube and
heat it up until it changes color completely (usually it will turn
white.) This means all the water of hydration (sometimes called
water of crystallization) has vaporized. Now, get another good
accurate mass for the anhydrate. Work out the ratio of masses, and
do a little stoichiometry with the molar mass of water (18
grams/mole.) You should end up with a certain number of moles of
water per moles of substance.
Copper(II) sulfate is an easy one to do. When you do all the
math, you end up with a ratio of 5 moles of water to every 1 mole
of anhydrate, so the formula for copper(II) sulfate hydrate works
out to be: CuSO4-5H2O.

###### Asked in Chemistry, Math and Arithmetic, Percentages, Fractions, and Decimal Values

### What are the formulas involving hydrates?

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.

###### Asked in Biology, Chemistry, Genetics

### Describe the role of water in a dehydration reaction?

Water will be a product in a dehydration reaction. For example,
when copper(II) sulfate hydrate is heated, the water of
crystallization vaporizes, leaving behind copper(II) sulfate
anhydrate. The equation is:
CuSO4.5H2O --> CuSO4 + 5H2O
Likewise, during dehydration synthesis (which is how more
complex sugars are formed from simple sugars), sucrose can be
formed from a glucose molecule and a fructose molecule. The
equation is:
C6H12O6 (glucose) + C6H12O6 (fructose) --> C12H22O11 +
H2O

###### Asked in Health, Salary and Pay Rates, Waste and Recycling, Gallbladders and Bile

### What causes the body to make to much creatine?

If it is your body, you may have a kidney problem, or the
beginnings of one. A high nitrogen level in the blood can cause the
creatinine level to elevate. Creatinine is an anhydrate of
creatine. Notice the difference in the spelling of the two.Creatine
is an alkaloid or amino acid present in muscle tissue.Creatinine is
excreted by the urine.A urine test along with a blood test
determines if the kidneys are functioning properly. Anabolic
steroid use will elevate creatinine levels, but many other drugs
can do the same. If you are using any medications, legal or not,
you may want to increase your intake of water. If unprescribed, you
may want to discontinue use until your levels return to normal.