Kontrolnaia Rabota Nomer 3 Po Khimii 8 Klass Kuznetsova Levkin Apr 2026

) and the presence of oxygen (oxygen-containing vs. oxygen-free).

Inorganic chemistry in the 8th grade is built upon the classification and interaction of four primary groups: oxides, bases (hydroxides), acids, and salts. Mastering these involves understanding their chemical formulas, nomenclature, and how they react with one another to form new substances. ) and the presence of oxygen (oxygen-containing vs

: They are generally divided into basic oxides (typically formed by metals like MgOcap M g cap O ) and acidic oxides (formed by non-metals like CO2cap C cap O sub 2 P2O5cap P sub 2 cap O sub 5 For example, reacting a basic oxide ( MgOcap

: While students primarily focus on normal (middle) salts like BaSO4cap B a cap S cap O sub 4 AlPO4cap A l cap P cap O sub 4 , the curriculum also introduces acid salts (e.g., NaHCO3cap N a cap H cap C cap O sub 3 ) and basic salts . ) and the presence of oxygen (oxygen-containing vs

A significant portion of the control work involves writing to demonstrate the "genetic link" between these classes. For example, reacting a basic oxide ( MgOcap M g cap O ) with an acid ( H2SO4cap H sub 2 cap S cap O sub 4 ) yields a salt ( MgSO4cap M g cap S cap O sub 4 ) and water ( H2Ocap H sub 2 cap O

: A critical distinction is between alkalis (soluble bases like KOHcap K cap O cap H NaOHcap N a cap O cap H ) and insoluble bases.

Salts are the product of replacing hydrogen in an acid with a metal or replacing hydroxyl groups in a base with an acid residue.