The molecular mass of CaCO₃ (calcium carbonate) is 100 g/mol. This is calculated by adding the atomic masses of all atoms in one molecule of calcium carbonate: one calcium atom (Ca), one carbon atom (C), and three oxygen atoms (O).
Molecular mass of CaCO₃ = 100 g/mol
CaCO₃ = Ca (40) + C (12) + 3×O (48) = 100
CaCO₃ forms: Limestone, Marble, Chalk, Calcite
CaCO₃ + heat → CaO + CO₂ (thermal decomposition)
CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂ (acid reaction)
Lime water test: CO₂ turns Ca(OH)₂ solution milky (forms CaCO₃)
Formula: CaCO₃ = Ca + C + O₃
Atomic masses (from periodic table):
Calculation: Molecular mass of CaCO₃ = Mass of Ca + Mass of C + Mass of 3O = 40 + 12 + (3 × 16) = 40 + 12 + 48 = 100 g/mol
Answer: Molecular mass of CaCO₃ = 100 g/mol
Chemical formula: CaCO₃ Common name: Calcium carbonate Other names: Calcite, Limestone, Chalk, Marble (all are forms of CaCO₃) Physical form: White solid, odourless, insoluble in water Molecular mass: 100 g/mol
Occurrence in nature: CaCO₃ is one of the most abundant minerals on Earth. It is found as:
Common reactions tested in exams:
Molecular mass: Mass of one molecule of a substance in atomic mass units (u). For CaCO₃ = 100 u. Molar mass: Mass of one mole (6.022 × 10²³ molecules) of a substance in grams. For CaCO₃ = 100 g/mol.
Numerically, molar mass and molecular mass are equal in value but differ in units (g/mol vs u). In most exam problems, both terms are used interchangeably.
The molecular mass of CaCO₃ (calcium carbonate) is 100 g/mol. Calculation: Ca (40) + C (12) + 3×O (3×16 = 48) = 40 + 12 + 48 = 100 g/mol.
Add the atomic masses of all atoms: CaCO₃ has 1 Ca + 1 C + 3 O. Atomic masses: Ca = 40, C = 12, O = 16. So: 40 + 12 + (3 × 16) = 40 + 12 + 48 = 100 g/mol.
Calcium carbonate (CaCO₃) occurs naturally in several forms: Limestone (sedimentary rock used in cement), Marble (metamorphic rock used in construction and sculpture), Chalk (soft form used in writing), and Calcite (crystalline mineral). All have the same chemical formula CaCO₃ but different physical structures.
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