10034-76-1 Usage
Chemical Properties
white or slightly off-white powder or granules
Industrial uses
Gypsum is the most common sulfate mineral,characterized by the chemical formulaCaSO4 · 2H2O; it shows little variation from thiscomposition.Gypsum is one of the several evaporite minerals.This mineral group includes chlorides,carbonates, borates, nitrates, and sulfates. Theseminerals precipitate in seas, lakes, caves, andsalt flats due to concentration of ions by evaporation.When heated or subjected to solutionswith very large salinities, gypsum converts tobassanite (CaSO4.H2O) or anhydrite (CaSO4).Under equilibrium conditions, this conversionto anhydrite is direct. The conversion occursabove 42°C in pure water.Gypsum is used for making building plaster,wallboard tiles, as an absorbent for chemicals,as a paint pigment and extender, and forcoating papers. Natural gypsum of California,containing 15 to 20% sulfur, is used for producingammonium sulfate for fertilizer. Gypsumis also used to make sulfuric acid by heatingto 1093°C in an air-limited furnace. Theresultant calcium sulfide is reacted to yield limeand sulfuric acid. Raw gypsum is also used tomix with portland cement to retard the set.Compact massive types of the mineral are usedas building stones.
Purification Methods
Its solubility in H2O is 0.2parts/100 at 18.75o. It dehydrates completely >650o. Dry it below 300o to give a solid with estimated pore size ca 38% of volume. Anhydrous CaSO4 (Drierite) has a high affinity for H2O and will absorb 6.6% of its weight of H2O to form the hemihydrate (gypsum). It sets to a hard mass with H2O; hence it should be kept in a tightly sealed container. The solubility of gypsum in H2O is unusual: 0.176% at 0o, 0.209% at 30o, 0.210 at 40o, 0.204 at 50o and 0.200 at 60o. [Hulett J Am Chem Soc 27 49 1905, James & Partington J Chem Soc 107 1019 1915, Namba J Soc Chem Ind 40 2797 1920.]
Check Digit Verification of cas no
The CAS Registry Mumber 10034-76-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,0,0,3 and 4 respectively; the second part has 2 digits, 7 and 6 respectively.
Calculate Digit Verification of CAS Registry Number 10034-76:
(7*1)+(6*0)+(5*0)+(4*3)+(3*4)+(2*7)+(1*6)=51
51 % 10 = 1
So 10034-76-1 is a valid CAS Registry Number.
InChI:InChI=1/Ca.H2O4S.H2O.2H/c;1-5(2,3)4;;;/h;(H2,1,2,3,4);1H2;;/p-2/rCaH2.H2O4S.H2O/c;1-5(2,3)4;/h1H2;(H2,1,2,3,4);1H2/p-2
