Calcium Standard - ≥99.5% metals basis , CAS No.7440-70-2

CAS: 7440-70-2 Cat. No.: C110720 Formula: Ca Molecular Weight: 40.08 Beilstein Registry Number: 4241647 EC Number: 231-179-5

GRADE & PURITY ≥99.5% metals basis

Synonyms

Calcium crystalline dendritic pieces | Calcium, SAJ first grade, >=99.5% | Erythra-Derm | Blood Coagulation Factor IV | Calcium 40 | CHEBI:29320 | Ostreae Concha, Calcium | C000001000 | Ca(0) | Calcium turnings, 2N | Factor IV, Coagulation | OnlyCal | Cal

Storage

Room temperature,Argon charged

Shipped In

FedEx DG Service

Specifications

Synonyms

Calcium crystalline dendritic pieces | Calcium, SAJ first grade, >=99.5% | Erythra-Derm | Blood Coagulation Factor IV | Calcium 40 | CHEBI:29320 | Ostreae Concha, Calcium | C000001000 | Ca(0) | Calcium turnings, 2N | Factor IV, Coagulation | OnlyCal | Cal

Specifications & Purity

≥99.5% metals basis

Storage

Room temperature,Argon charged

Shipped In

FedEx DG Service

Purity

≥99.5% metals basis

Names and Identifiers

Canonical Smiles

[Ca]

IUPAC Name

calcium

InChIKey

OYPRJOBELJOOCE-UHFFFAOYSA-N

INCHI

1S/Ca

Isomeric SMILES

[Ca]

WGK Germany

1

UN Number

1401

Packing Group

II

Molecular Weight

40.08

Beilstein

4241647

Reaxy-Rn

4241647

Reaxys-RN_link_address

https://www.reaxys.com/reaxys/secured/hopinto.do?context=S&query=IDE.XRN=4241647&ln=

Taxonomic Classification

Taxonomy Tree

• Kingdom Inorganic compounds
  • Superclass Homogeneous metal compounds
    • Class Homogeneous alkaline earth metal compounds

• Kingdom: Inorganic compounds
• Superclass: Homogeneous metal compounds
• Class: Homogeneous alkaline earth metal compounds
• Subclass: Not available
• Intermediate Tree Nodes: Not available
• Direct Parent: Homogeneous alkaline earth metal compounds
• Alternative Parents: Not available
• Molecular Framework: Not available
• Substituents: Homogeneous alkaline earth metal
• Description: This compound belongs to the class of inorganic compounds known as homogeneous alkaline earth metal compounds. These are inorganic compounds containing only metal atoms,with the largest atom being a alkaline earth metal atom.
• External Descriptors: elemental calcium

Data sources

1. Djoumbou Feunang Y, Eisner R, Knox C, Chepelev L, Hastings J, Owen G, Fahy E, Steinbeck C, Subramanian S, Bolton E, Greiner R, and Wishart DS. ClassyFire: Automated Chemical Classification With A Comprehensive, Computable Taxonomy. Journal of Cheminformatics, 2016, 8:61.

DOI: 10.1186/s13321-016-0174-y

Chemical and Physical Properties

• Sensitivity: moisture sensitive.Air Sensitive
• Boil Point(°C): 1484°C
• Melt Point(°C): 839±2°C
• Molecular Weight: 40.080 g/mol
• Hydrogen Bond Donor Count: 0
• Hydrogen Bond Acceptor Count: 0
• Rotatable Bond Count: 0
• Exact Mass: 39.9626 Da
• Monoisotopic Mass: 39.9626 Da
• Topological Polar Surface Area: 0.000 Ų
• Heavy Atom Count: 1
• Formal Charge: 0
• Complexity: 0.000
• Isotope Atom Count: 0
• Defined Atom Stereocenter Count: 0
• Undefined Atom Stereocenter Count: 0
• Defined Bond Stereocenter Count: 0
• Undefined Bond Stereocenter Count: 0
• The total count of all stereochemical bonds: 0
• Covalently-Bonded Unit Count: 1

XLogP3

Application Protocols

No tested application protocols are provided for this item in the Product Data.

Guidance

• For analytical use (e.g., employing calcium metal as a solid standard), follow your instrument manufacturer’s calibration procedures and use appropriate certified references for traceability.
• For synthetic use as a reductant or organometallic precursor, consult peer-reviewed literature and standard organometallic technique manuals. Validate on small scale under inert atmosphere before scale-up.

Note: Because protocols depend strongly on the intended application and form of the metal (shot, granules, turnings, powder), refer to the lot-specific CoA/SDS and institutional SOPs.

Biological Roles

Not directly applicable to the supplied form (elemental calcium metal). The product is intended for research/lab use and is provided as a reactive metal under inert gas.

General biochemical context (literature; for conceptual reference only)

• Calcium as Ca2+ is a ubiquitous signaling ion regulating muscle contraction, neurotransmission, secretion, and enzyme activation. Cytosolic Ca2+ transients are decoded by proteins such as calmodulin and troponin.
• Structural roles: Ca2+ stabilizes cell walls (plants, pectin crosslinking), mineralized tissues (hydroxyapatite in bone/teeth), and numerous extracellular proteins (C2, EGF-like domains).
• Homeostasis: maintained by channels, pumps (SERCA/PMCA), exchangers, and intracellular stores (ER/SR) with buffering by proteins and organelles (mitochondria).
• Speciation/complexation: Ca2+ forms complexes with carboxylates, phosphates, and chelators (EDTA/EGTA), dramatically affecting bioavailability and activity.

Important distinction

• These roles pertain to the divalent ion in aqueous/physiological environments, not to the reactive elemental metal in this listing. Do not introduce calcium metal into biological systems. For biochemical work, use appropriate calcium salt standards or certified solutions.

Buffer Applications

Not applicable to elemental calcium metal.

Guidance

• Buffers pertain to acid/base pairs in solution. Calcium metal reacts with water/protic media and is not used to prepare buffer systems directly.
• For experiments requiring controlled Ca2+ activity in buffered solutions, use soluble calcium salts (e.g., CaCl2, Ca(NO3)2) and appropriate chelators (EGTA/EDTA) to define free calcium; that is outside the scope of this product.

Green Alternatives

Context: Calcium metal is a powerful reductant and oxygen scavenger. Greener choices depend on the transformation and hazard profile.

Comparison (literature-based, qualitative)

• Calcium vs. magnesium or zinc
  • Pros (Ca): stronger reducing potential; can access transformations not feasible with Mg/Zn; less toxic profile than many transition metals.
  • Cons (Ca): water-reactive; H2 evolution and potential fire risk; often requires activation and strictly anhydrous conditions.
• Calcium vs. sodium/potassium
  • Pros (Ca): generally less pyrophoric than alkali metals; lower volatility; safer handling than Na/K dispersions.
  • Cons (Ca): still water-reactive; can generate heat and hydrogen; limited substrate scope without activation.
• Calcium vs. samarium(II) iodide (SmI2)
  • Pros (Ca): earth-abundant, lower cost, reduced rare-earth environmental burden.
  • Cons (Ca): lower chemoselectivity in some reductions; more challenging control of reactivity.

Greener process considerations

• Solvent choice: replace THF with 2-MeTHF or CPME (biorenewable, higher boiling, improved safety) where compatible.
• Atom economy: reductions that form simple salts (CaX2) can be efficient but generate inorganic waste; plan for recycling or minimal stoichiometry.
• Energy: Rieke-type activations consume additional reagents/energy; consider catalytic alternatives (e.g., hydrogenation or electroreduction) if compatible with substrate selectivity.

Bottom line: For reductions where Mg or Zn suffice, they may offer safer, lower-hazard handling. Where Ca’s reducing strength is essential, mitigate impacts via greener ethers, tight solvent recycle, and careful hydrogen management.

Pharmaceutical Uses

Not applicable to the elemental metal as an excipient or formulation aid.

General context (literature)

• Pharmaceutical and nutraceutical applications employ specific calcium salts (e.g., carbonate, citrate, phosphate) as actives or excipients. Elemental calcium metal is not used in formulations.
• If your interest is in analytical calibration within GMP settings (e.g., XRF of device alloys or preparation of Ca2+ reference solutions), ensure traceability to certified reference materials and comply with pharmacopeial chapters on elemental impurities testing (e.g., USP <232>/<233>) and instrumental methods.

This product is for research use only (as specified) and is not intended for human or veterinary use, diagnostics, or as a drug substance.

Physical Properties

Item-specific specs

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.

Literature/general values for elemental calcium (for planning only; not product specifications)

• Atomic weight: 40.078 g/mol (IUPAC; literature)
• Density: ~1.55 g/cm³ at 20 °C (literature)
• Melting point: ~842 °C (literature)
• Boiling point: ~1484 °C (literature)
• Electrical/thermal: good electrical and thermal conductor (metallic; literature)
• Solubility: insoluble in common organic solvents and water as a bulk metal; reacts slowly with water and protic solvents to form Ca(OH)2 (or Ca salts) with H2 evolution (literature)
• Reactivity: readily oxidizes/tarnishes in air to CaO/Ca(OH)2; reaction rate increases with humidity and temperature (literature)

Optical/other

• Refractive index: not applicable to bulk metallic solids.
• LogP/pKa: not applicable to the elemental metal; such parameters pertain to molecular species in solution.

Practical notes (general)

• Fresh metallic surfaces are silvery; exposure leads to a dull gray oxide/hydroxide coating.
• Finely divided calcium (turnings, powder) is more reactive than larger granules/shot due to surface area. Handle under inert atmosphere.

Reminder: Only the storage condition “Room temperature, Argon charged” is specified for this item; all numerical values above are literature guidance and not lot specifications.

Quality & Grades

Item-specific quality fields

• Grade/Purity: Not specified for this item; refer to CoA/Spec Sheet.

Interpretive guidance (general; not product specifications)

• “Calcium Standard” may refer to an elemental metal supplied for instrument calibration (e.g., XRF) or as a defined source for preparing calibration solutions (e.g., ICP after controlled dissolution). In absence of an explicit assay, treat it as a research-grade metal supplied under inert gas, suitable for laboratory and materials applications.
• Typical grades for elemental metals include: metallurgical grade, reagent grade, high-purity (e.g., 99.0–99.99%), and ultra-high-purity (trace-metal basis). Each step up tightens limits on metallic and nonmetallic impurities (Na, K, Mg, Fe, Al, Si, C, O, N, S, P), surface oxides, and moisture content.
• If using for trace analysis (e.g., ICP standard preparation), obtain the lot-specific CoA documenting elemental impurity profile and uncertainty budget. For physical metallurgy or synthetic reductions, bulk metallic purity and surface condition are usually the critical parameters.

Stabilization and packaging (item-specific + general)

• Storage: Room temperature, Argon charged (from Product Data). Inert backfill minimizes oxidation and moisture uptake.
• Packaging implications: containers should be airtight, low-permeability, and compatible with metals; re-seal under inert gas after opening. If subdividing, use an inert-atmosphere glovebox.

Conclusion

• Without a stated grade, do not assume trace-metal-basis purity. Verify specifications on the CoA/Spec Sheet for your lot and application.

Reaction & Applications

Research-use contexts for elemental calcium (general literature; expand as relevant to “Calcium Standard”)

Analytical/calibration

• Solid elemental standards: calcium metal can serve as a matrix-matched reference for XRF or spark-OES calibration after surface preparation. For wet-chemical techniques (ICP-OES/MS), standards are more commonly prepared from certified calcium salt/solution; however, metal can be dissolved under controlled conditions to generate stock solutions when traceability is established.

Synthetic and materials chemistry

• Reducing agent: calcium metal acts as a strong reductant (E° Ca2+/Ca ≈ −2.87 V, literature), enabling reductions of functional groups and deoxygenation when activated (e.g., I2, NH4I, or catalytic salts) in ethers or hydrocarbons.
• Oxidative insertion: formation of organocalcium species from aryl/alkyl halides under activating conditions (often I2-initiated) can participate in Barbier-type additions to carbonyls or be transmetalated (e.g., to Cu, Pd, or Zn) for cross-couplings.
• Rieke calcium: highly activated, finely divided calcium prepared by reducing CaI2 or CaCl2 with alkali metals enables more rapid insertions and reductions at lower temperatures.
• Getter/Scavenger: calcium effectively scavenges oxygen, sulfur, and nitrogen species; it is used as a deoxidizer/desulfurizer in metallurgical operations and in sealed systems to maintain low O2/H2O.
• Alloying/Intermetallics: synthesis of Ca-containing intermetallics, phosphides, silicides, and borides often uses calcium metal as the Ca source under inert/reducing atmospheres.

Practical tips

• Surface activation (filings/turnings, abrasion, iodine activation) greatly impacts reaction rates.
• Maintain rigorously anhydrous and oxygen-free conditions; exothermic reaction with protic media evolves H2.

Reaction Conditions

General literature guidance for reactions involving elemental calcium (adapt to your substrate/system; not product specifications)

• Atmosphere: rigorously inert (Ar or N2). Use glovebox or Schlenk techniques.
• Solvents: dry, oxygen-free ethers (THF, DME, diglyme, 2-MeTHF) or hydrocarbons (toluene, heptane); often mixed to balance solvation and reactivity.
• Activation: catalytic I2, NH4I, or halide salts; mechanical abrasion; or use of Rieke calcium for higher reactivity.

Selected use-cases

• Oxidative insertion to form organocalcium
  • Typical setup: Ca turnings with aryl iodide (1.0 equiv) in dry THF, catalytic I2 (1–10 mol%).
  • Temperature/time: 20–60 °C, 1–6 h, depending on substrate and activation.
  • Follow-up: in situ addition to electrophiles (e.g., aldehydes) or transmetalation to Zn/Cu for cross-coupling.
• Reductive dehalogenation/coupling
  • Conditions: Ca (2–4 equiv), dry THF or 2-MeTHF, I2 activation; 0–25 °C to reflux; times from 1–12 h.
• Metallothermic reductions (materials)
  • Solid-state reactions at elevated temperatures (200–900+ °C) under inert or vacuum; stoichiometric Ca with target oxide/salt.

Yields/selectivity

• Highly substrate-dependent; organocalcium formations and Barbier additions can afford moderate to high yields under optimized conditions. Activated (Rieke) Ca generally increases rates and conversions.

Safety note

• Carefully manage exotherms and hydrogen evolution. Quench unreacted Ca under inert conditions with dry isopropanol or a controlled, chilled alcoholic solution—never water directly. Always consult primary literature and conduct small-scale trials.

Safety & Handling

Item-specific hazard fields

• GHS Classification: Not specified for this item; refer to SDS.
• Signal Word / H-Statements / Pictograms: Not specified for this item; refer to SDS.
• Shipping: FedEx DG Service (dangerous goods) per Product Data.

General safety guidance for elemental calcium (literature; consult SDS for your lot)

• Principal hazards: reacts with water and moisture to release hydrogen gas; heat from reaction can ignite H2. Finely divided calcium can ignite in air. Forms caustic hydroxide upon contact with water.
• Incompatibilities: water, humid air, acids (vigorous reaction), oxidizers, halogens, CO2 under certain conditions (can form carbonate on surfaces). Avoid contact with protic solvents.
• Atmosphere control: handle in a dry inert environment (argon or nitrogen). Open containers only inside a glovebox or using Schlenk techniques. Keep containers tightly sealed and argon charged (as specified for this item).
• PPE: safety glasses or face shield, lab coat, and appropriate chemically resistant gloves. Use a dust mask/respirator if generating particulates.
• Fire response: do NOT use water or CO2 on metal fires. Use Class D extinguishing media (e.g., dry sand, Met-L-X). Evacuate area if hydrogen is suspected.
• Spill response: cover small spills with dry sand or Class D agent; collect under inert atmosphere. Do not add water.
• First aid (overview): for skin/eye contact with residues, rinse cautiously with water after brushing away loose particles; seek medical attention. If inhaled (dust), move to fresh air. If ingested, rinse mouth; do not induce vomiting; seek medical attention.

Always defer to the product’s SDS and your institution’s EHS procedures for authoritative guidance.

Solvent Selection

Not typically applicable: this product is a solid elemental metal, not a solvent.

Useful context (general)

• When calcium is used as a reagent, reactions are commonly conducted in aprotic, anhydrous solvents such as THF, 2-MeTHF, CPME, glymes, toluene, or hexanes. Solvent choice balances solvation of counterions (e.g., Ca2+) with stability of substrates and minimal proton sources.
• Avoid protic solvents (water, alcohols) and acidic media, which react with calcium to evolve hydrogen and destroy the metal.

Selection tips (literature guidance)

• Polar ethers (THF, DME, diglyme) can accelerate oxidative insertions into organic halides (formation of organocalcium intermediates) and facilitate electron transfer.
• Less polar hydrocarbons (toluene, heptane) help moderate over-reduction and can suppress side reactions when a co-solvent ether is present for activation.

If your application involves solution-phase calcium salts (Ca2+), solvent selection is entirely different and driven by salt identity and target system; that is outside the scope of this elemental metal listing.

Storage & Reconstitution

Item-specific storage/shipping

• Storage Conditions: Room temperature, Argon charged (from Product Data). Keep container tightly sealed under inert gas to minimize oxidation and moisture uptake.
• Shipped In: FedEx DG Service (from Product Data).

General storage guidance (elemental calcium)

• Store in a dry, inert atmosphere (Ar preferred), away from moisture, acids, and oxidizers. Use secondary containment to segregate from incompatible materials.
• Open only in a glovebox or using Schlenk techniques. Reseal under argon promptly after use. For long-term storage, periodic headspace purge with Ar can help maintain inert conditions.
• Inspect periodically for surface oxidation/tarnish. If necessary and safe, remove outer oxide layers mechanically inside an inert environment prior to use.

Reconstitution/Preparation

• Not specified for this item; refer to CoA/Spec Sheet. Elemental calcium is typically used as supplied. If preparing solutions or reagents from the metal, follow application-specific, vetted procedures under inert conditions and consult the SDS.

Disposal

• Quench residual small fragments cautiously under inert conditions with a dry, anhydrous alcohol before aqueous workup. Dispose of resulting inorganic salts according to local regulations and your EHS guidance.

Research Use Note

• For research use only (from Product Data). Not for human or veterinary use.

Structure & Identity

Brief description: This product corresponds to elemental calcium (zero‑valent Ca), an alkaline‑earth metal (Group 2) typically supplied under inert gas to prevent oxidation.

Item-specific facts (from Product Data)

• SKU: C110720
• Product Name: Calcium Standard
• CAS: 7440-70-2 (elemental calcium)
• CID: 5460341
• InChIKey: 270937 (as provided)
• SMILES: Not specified for this item; refer to CoA/Spec Sheet.

Literature/typical identifiers (general knowledge)

• Element symbol: Ca
• Oxidation state (as supplied): 0 (metal). Common ionic state in solution: Ca2+ (not the supplied form).
• Molecular formula (elemental): Ca (literature)
• Molecular weight (atomic weight): 40.078 g/mol (IUPAC 2021; literature)

Structural features (general description)

• 2D/line representation: single elemental atom “Ca”; no covalent bonds in the pure metal.
• Extended structure: metallic lattice (crystal structure is temperature/pressure dependent; details vary in the literature). Surface readily forms a thin oxide/hydroxide layer in air.
• Functional groups: none; metallic element.
• Stereochemistry: not applicable.

Notes

• Because this is a metal, conventional organic identifiers (canonical SMILES for molecules, InChI layers describing bonds/stereochemistry) are generally not used or may be database placeholders. Always rely on the product’s CoA/SDS for definitive identifiers of the supplied lot/form.

Synthetic Utility

Elemental calcium offers versatile reactivity in synthesis and materials preparation (literature guidance):

• Strong reductant: Calcium can reduce a variety of functional groups under activating conditions. Examples include dehalogenation, reductive coupling, and deoxygenation. Iodine-activated Ca in ethers promotes single-electron transfer pathways.
• Organocalcium intermediates: Oxidative insertion of Ca into C–X bonds (particularly aryl/alkyl iodides and bromides) yields organocalcium reagents that can participate in Barbier-type additions to carbonyls or be transmetalated to Cu, Pd, or Zn for cross-coupling sequences.
• Rieke calcium: Highly activated, high-surface-area Ca enables room-temperature insertions and reactions otherwise sluggish with bulk metal. Prepared by reducing CaI2 or CaCl2 with alkali metals under inert conditions.
• Metallothermic synthesis: Calcium reduces metal oxides, sulfides, and phosphates to the corresponding metals/phases, useful for intermetallic, phosphide, boride, and silicide synthesis.
• Getter/scavenger: Employed to remove residual O2, H2O, S, and N from closed systems and melts.

Practical considerations

• Surface activation (fresh filings, abrasion, or halogen promoters) is often critical. Granule size and oxide coverage dictate kinetics.
• Strict exclusion of moisture/oxygen is mandatory; hydrogen evolution and heat release can be hazardous.
• Workup commonly yields CaX2 or Ca(OH)2 byproducts; plan for their safe quench and disposal.

Target Specificity

Not applicable. This product is an elemental metal reagent/standard, not a biological targeting reagent (e.g., antibody, enzyme inhibitor, ligand). No target specificity data are provided for this item.

Frequently Asked Questions

What does the trace-metals specification mean?

This product is specified at ≥99.5% on a trace-metals basis. That figure describes metallic impurity content rather than overall chemical assay, so it is the relevant specification for ICP-MS, semiconductor and battery applications. Lot-specific values are stated on the Certificate of Analysis.

How should this product be stored?

Store at room temperature under argon. It is supplied under an argon blanket; reseal under inert gas after each use.

How is this product shipped?

This product is classified as dangerous goods and ships via FedEx DG Service. Ground and other economy services are not available, and delivery to some destinations or address types may be restricted.

What are the CAS number, molecular formula and molecular weight?

The CAS Number is 7440-70-2, the molecular formula is Ca, and the molecular weight is 40.08 g/mol. InChIKey OYPRJOBELJOOCE-UHFFFAOYSA-N.

What documentation is provided?

Available product documentation, including Certificates of Analysis (COA), Safety Data Sheets (SDS), and specification sheets, is shown in the product document area. Document availability and access follow the current site policy.