TATA NAMA SENYAWA

Summary

This video tutorial covers the essential concepts of chemical nomenclature, focusing on naming ionic compounds, molecular compounds, acids, bases, hydrates, and organic compounds. The speaker explains the rules for naming ionic compounds based on cation and anion charges, the use of prefixes in molecular compound names, and the classification of acids and bases. The tutorial also touches on naming hydrates and introduces common organic compounds. With clear examples and explanations, viewers will gain a solid understanding of chemical naming conventions in both inorganic and organic chemistry.

Takeaways

• 😀 Naming ionic compounds involves two main parts: the cation (positive ion) and the anion (negative ion).
• 😀 Cations are usually metals, and their oxidation state is indicated by Roman numerals if necessary (e.g., Fe²⁺ as Iron(II)).
• 😀 Anions, often nonmetals or polyatomic ions, typically end in '-ide' for simple ions (e.g., chloride for Cl⁻).
• 😀 Polyatomic ions like sulfate (SO₄²⁻) and nitrate (NO₃⁻) have specific names and are treated as single entities in compound naming.
• 😀 For molecular compounds, prefixes like mono-, di-, tri- are used to denote the number of atoms present (e.g., N₂O₅ as dinitrogen pentoxide).
• 😀 The prefix 'mono-' is generally omitted for the first element in molecular compound names (e.g., CO₂ is carbon dioxide, not monocarbon dioxide).
• 😀 Acids are named based on the anion they contain, with 'acid' added to the name of the anion (e.g., HCl as hydrochloric acid).
• 😀 Bases are compounds with hydroxide ions (OH⁻) and are named similarly to ionic compounds (e.g., NaOH as sodium hydroxide).
• 😀 Hydrates are compounds that contain water molecules, and their names include a prefix indicating the number of water molecules (e.g., CaSO₄·2H₂O as calcium sulfate dihydrate).
• 😀 Organic compounds, made up of carbon and hydrogen, are named based on functional groups and their bonding patterns (e.g., CH₄ as methane, C₂H₅OH as ethanol).

Q & A

What are ionic compounds, and how are they formed?

Ionic compounds are formed when positive ions (cations) and negative ions (anions) come together. This typically happens when a metal (which forms cations) reacts with a non-metal (which forms anions). The ions are held together by electrostatic forces, creating an ionic bond.

How are ionic compounds named?

Ionic compounds are named by stating the name of the cation (metal) followed by the name of the anion (non-metal), with the anion ending in '-ide'. For example, NaOH is named 'Sodium hydroxide'. If the metal comes from a transition element, a Roman numeral indicating the metal's charge is included, like in 'Iron(III) oxide' for Fe2O3.

What is the significance of Roman numerals in naming ionic compounds?

Roman numerals are used in the naming of ionic compounds when the metal in the compound can have multiple oxidation states. The numeral indicates the charge of the metal cation. For example, 'Copper(II) chloride' (CuCl2) indicates that copper has a +2 charge.

What are molecular compounds, and how are they named?

Molecular compounds consist of two or more non-metal atoms bonded together. They are named using prefixes to indicate the number of atoms of each element. For example, N2O5 is named 'Dinitrogen pentoxide', where 'di-' and 'penta-' are the prefixes for 2 and 5 atoms, respectively.

What is the rule for naming molecular compounds with non-metal elements?

When naming molecular compounds, the first element is named first, followed by the second element with an '-ide' suffix. Prefixes such as mono-, di-, tri-, etc., are used to indicate the number of atoms of each element, except for mono- on the first element.

What are acids, and how are they named?

Acids are compounds that contain hydrogen ions (H+) and an anion. When naming acids, if the anion is a simple element, the name of the acid is 'Hydro-' followed by the element's name with the suffix '-ic acid'. For example, HCl is 'Hydrochloric acid'. If the anion is polyatomic, the acid is named by changing the suffix of the anion to '-ic' or '-ous'. For example, H2SO4 is 'Sulfuric acid'.

How are bases named?

Bases are compounds that contain a cation and hydroxide ions (OH-). To name a base, first name the cation, followed by 'hydroxide'. For example, NaOH is named 'Sodium hydroxide', and Ca(OH)2 is named 'Calcium hydroxide'.

What are hydrates, and how are they named?

Hydrates are compounds that contain water molecules within their crystalline structure. The naming of hydrates involves stating the name of the salt first, followed by the number of water molecules using prefixes. For example, CaSO4·2H2O is named 'Calcium sulfate dihydrate'.

What is the rule for naming acids with polyatomic anions?

When naming acids with polyatomic anions, if the anion ends in '-ate', the acid will end in '-ic acid'. If the anion ends in '-ite', the acid will end in '-ous acid'. For example, H2SO4 (sulfate anion) is named 'Sulfuric acid', while H2SO3 (sulfite anion) is named 'Sulfurous acid'.

Can you give an example of a molecular compound where the prefix 'mono-' is not used on the first element?

Yes, in the compound CO (carbon monoxide), the prefix 'mono-' is not used for the first element (carbon), even though there is only one carbon atom. This is a special rule for molecular compounds where 'mono-' is omitted for the first element.