What is Platinum Definition Properties Reactions and Applications
Platinum is essential in chemistry and helps students understand various practical and theoretical applications related to this topic.
What is Platinum in Chemistry?
A platinum element refers to a rare, silvery-white, noble metal with the chemical symbol Pt and atomic number 78. This concept appears in chapters related to transition metals, periodic table trends, and coordination compounds, making it a foundational part of your chemistry syllabus.
Molecular Formula and Composition
The molecular formula of platinum is Pt. It consists of only platinum atoms and is categorized under transition metal elements. Platinum belongs to Group 10 of the periodic table and is part of the platinum group metals, which include palladium, rhodium, ruthenium, osmium, and iridium.
Preparation and Synthesis Methods
Industrial extraction of platinum usually starts with ores like sperrylite (PtAs2) and cooperite (PtS). The process involves crushing and grinding the ore, followed by froth flotation to concentrate platinum minerals.
The concentrate is then treated with aqua regia, which dissolves platinum to form chloroplatinic acid. After several purification steps, heating decomposes the ammonium salt to obtain pure, metallic platinum.
In laboratories, platinum is rarely synthesized due to its natural rarity and complex extraction but is purified from various minerals using similar chemical methods.
Physical Properties of Platinum
Platinum is a dense, malleable, ductile metal with a brilliant silver-white color. It does not tarnish in air and is highly resistant to corrosion, even at high temperatures.
Its melting point is about 1768°C and boiling point is 3825°C. Platinum is also an excellent conductor of electricity and has a very high density (21.45 g/cm3). It is softer than iron but harder than gold, making it strong for industrial and jewelry use.
Chemical Properties and Reactions
Platinum is known for its remarkable chemical inertness. It does not react with oxygen or water, and ordinary acids have little effect on it. However, platinum dissolves in aqua regia (a mixture of hydrochloric and nitric acids), forming chloroplatinic acid.
It exhibits common oxidation states of +2 and +4 and participates in redox and complex formation reactions, showing its strong tendency to form coordination compounds.
Frequent Related Errors
- Confusing platinum with similar-looking metals like silver or white gold.
- Incorrectly writing its electronic configuration as [Xe] 4f14 5d8 6s2 instead of [Xe] 4f14 5d9 6s1.
- Thinking platinum reacts with most acids, when only aqua regia truly dissolves it.
- Assuming platinum is as common as gold when it’s actually much rarer.
Uses of Platinum in Real Life
Platinum is widely used in both industry and everyday life. Its main applications include:
- Catalytic converters in car exhaust systems (reducing pollution).
- High-end jewelry and watches for its hypoallergenic nature and permanence.
- Production of nitric acid, fertilizers, and silicones as a chemical catalyst.
- Medical devices, dental fillings, and pacemakers due to its inertness.
- In electronics, used for hard disk coatings and fuel cell technology.
You can learn more about metals used in daily life in this Vedantu article on the uses of metals.
Relation with Other Chemistry Concepts
Platinum is closely related to topics such as d-block elements and transition elements, helping students understand why these metals show variable oxidation states and form colored compounds.
Its chemical stability also links to the topic of noble metals and chemical inertness. Understanding its extraction process also supports the study of extraction of metals.
Step-by-Step Reaction Example
1. Start with platinum metal exposure to aqua regia.2. Aqua regia dissolves platinum, forming hexachloroplatinic acid (H2PtCl6).
3. The chemical equation is:
4. Heating with ammonium chloride converts the acid to ammonium hexachloroplatinate.
5. Strong heating decomposes it to pure platinum metal.
Lab or Experimental Tips
Remember platinum’s electron configuration as [Xe] 4f14 5d9 6s1—it’s a notable exception to the usual order. Vedantu educators emphasize learning such unique patterns to tackle tricky periodic table questions easily.
Try This Yourself
- Write the condensed electron configuration of platinum.
- Name two ores from which platinum is extracted.
- Explain why platinum is used in medical implants.
Final Wrap-Up
We explored platinum—its structure, properties, reactions, and real-life importance. Its unique characteristics make it vital for industry and science. For more in-depth explanations and stepwise topic guides, check out live classes and notes available on Vedantu.
FAQs on Platinum in Chemistry Properties Structure and Uses
1. What is platinum in chemistry?
Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, silvery-white transition metal in Group 10 of the periodic table. Key properties include:
- High resistance to corrosion and oxidation
- Excellent catalytic activity
- High melting point (about 1768 °C)
- Ability to form complex ions and coordination compounds
2. What is the electron configuration of platinum?
The electron configuration of platinum (Pt) is [Xe] 4f14 5d9 6s1. This configuration shows an irregular filling pattern due to the stability of partially filled d-orbitals. Key points:
- Atomic number = 78 electrons
- Belongs to the d-block (transition metals)
- Exhibits variable oxidation states because of its 5d and 6s electrons
3. What are the common oxidation states of platinum?
The most common oxidation states of platinum are +2 and +4. These states are frequently observed in platinum compounds and complexes.
- Pt(II): Found in compounds like PtCl2 and square-planar complexes
- Pt(IV): Found in compounds such as PtCl4 and octahedral complexes
- Less common states include 0, +1, +3, and +6
4. Why is platinum used as a catalyst?
Platinum is used as a catalyst because it can adsorb reactant molecules and lower the activation energy of chemical reactions. Its catalytic properties arise from:
- Partially filled d-orbitals that facilitate bond formation and breaking
- High surface reactivity
- Resistance to corrosion at high temperatures
5. What is cisplatin and why is it important?
Cisplatin is a platinum-based coordination compound with the formula Pt(NH3)2Cl2 used as an anticancer drug. It is a Pt(II) complex with square-planar geometry. Key features:
- Contains two ammonia (NH3) ligands and two chloride (Cl-) ligands
- The ligands are in a cis configuration
- Binds to DNA and interferes with cell division
6. How does platinum react with acids?
Platinum does not react with most single acids but dissolves in aqua regia, a mixture of concentrated HCl and HNO3. Platinum is highly resistant to corrosion, but in aqua regia it forms chloroplatinic acid:
- Overall simplified reaction: Pt(s) + 4HNO3(aq) + 6HCl(aq) → H2PtCl6(aq) + 4NO2(g) + 4H2O(l)
- Forms the complex ion [PtCl6]2-
7. What type of bonding does platinum form in its compounds?
Platinum primarily forms metallic bonds in the solid state and coordinate covalent bonds in its complexes. In detail:
- Metallic bonding in elemental Pt(s)
- Ionic and covalent character in compounds like PtCl2
- Coordinate (dative) bonds in complexes such as [Pt(NH3)4]2+
8. What is the molar mass of platinum?
The molar mass of platinum (Pt) is 195.08 g·mol-1. This value represents the mass of one mole of platinum atoms. For calculations:
- 1 mole of Pt = 195.08 g
- Number of atoms in 1 mole = 6.022 × 1023 atoms (Avogadro’s number)
9. What is the crystal structure of platinum?
Platinum has a face-centered cubic (FCC) crystal structure. In this arrangement:
- Atoms are located at each corner and the center of each face of the cube
- Each atom has a coordination number of 12
- This structure contributes to its high density and ductility
10. How is platinum extracted from its ores?
Platinum is extracted from sulfide ores through crushing, flotation, smelting, and chemical refining. The main steps include:
- Concentration of platinum-containing sulfide ores
- Smelting to produce a matte containing platinum group metals
- Chemical treatment with aqua regia to form soluble complexes like H2PtCl6
- Reduction to obtain pure Pt metal
