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Molar Mass Lab/Molar mass for K2CO3
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Molar Mass of Potassium Carbonate (K2CO3)

Molar Mass of Potassium Carbonate is a key number in salt-related stoichiometry, especially when balancing reactants and products. Molar Mass of K₂CO₃ is 138.20 g/mol, based on 3 element types, with K contributing the largest share.

For fast checks, use the calculate molar mass, verify element values in the periodic table with molar mass, or explore more molar mass calculations.

Molar Mass of Potassium Carbonate is:

138.20 g/mol

Molar Mass of K₂CO₃ equals 138.20 g/mol, so 138.20 grams is one mole.

Element Breakdown Table

ElementCountAtomic massCalculationContribution
Potassium (K)239.102 x 39.1078.20 g/mol
Carbon (C)112.011 x 12.0112.01 g/mol
Oxygen (O)316.003 x 16.0048.00 g/mol
Final molar mass
78.200 + 12.010 + 48.000
138.20 g/mol

Computing Molar Mass of Potassium Carbonate Step by Step

Molar Mass of Potassium Carbonate: Step-by-Step Calculation

1. Identify Element Counts

Read K2CO3 and list how many atoms of each element are present:

  1. 2 atoms of Potassium (K)
  2. 1 atom of Carbon (C)
  3. 3 atoms of Oxygen (O)

2. Determine Atomic Masses

Look up each element mass from the periodic table:

  1. Potassium (K) ~= 39.098 g/mol
  2. Carbon (C) ~= 12.011 g/mol
  3. Oxygen (O) ~= 15.999 g/mol

3. Multiply Atomic Mass by Quantity

Multiply atom count by atomic mass for each element:

  • Potassium (K): 2 x 39.098 = 78.200 g/mol
  • Carbon (C): 1 x 12.011 = 12.010 g/mol
  • Oxygen (O): 3 x 15.999 = 48.000 g/mol

4. Sum Total Molar Mass

Add all contributions to get the final molar mass in g/mol.

Molar Mass = (2 x 39.098 + 1 x 12.011 + 3 x 15.999)

Molar Mass = 78.200 + 12.010 + 48.000

Molar Mass = 138.200 g/mol

Final rounded value shown on this page: 138.20 g/mol.

Visual Calculation Chart

ElementCountMassCount x massContribution
Potassium (K)239.0982 x 39.098= 78.200
Carbon (C)112.0111 x 12.011= 12.010
Oxygen (O)315.9993 x 15.999= 48.000
Final molar mass
78.200 + 12.010 + 48.000
= 138.200

Easy Way to Remember

Easy way to remember Molar Mass of Potassium Carbonate

  • Molar Mass of Potassium Carbonate: count atoms, multiply masses, and add totals.
  • Write each element in a table so you do not miss subscripts.
  • Keep 2-3 decimals during steps, then round only at the end.

Sample Reactions

TypeReaction
Double displacementAgNO₃ + NaCl → AgCl + NaNO₃
Acid-salt reactionNa₂CO₃ + ₂HCl → ₂NaCl + H₂O + CO₂

Do You Know?

Potassium Carbonate contains 3 element types: K, C, O.

K contributes the largest share of this compound's total molar mass.

In K₂CO₃, O appears with the highest atom count.

Its molar mass is 138.20 g/mol, which is used directly in gram-to-mole conversions.

A common reaction for Potassium Carbonate is double displacement (AgNO₃ + NaCl → AgCl + NaNO₃).

Why This Compound Matters

Potassium Carbonate appears in ionic-reaction practice and precipitation examples in school chemistry.

Its molar mass helps students move quickly between grams, moles, and concentration problems.

Similar calculations can be compared with Potassium Hydrogen Carbonate (KHCO3) and Potassium Acetate (KC2H3O2).

Where This Is Used

  • Competitive exams and school chemistry tests.
  • Lab work when preparing measured solutions.
  • Real-world manufacturing and quality checks.

Common Mistakes When Calculating This

  • Skipping subscripts in K₂CO₃ and miscounting atoms.
  • Rounding atomic masses too early before finishing all multiplication steps.
  • Mixing up K element contribution with total molar mass.
  • Reporting a value without units; final answer should be in g/mol for Potassium Carbonate.

Spot a slip early by comparing your work with molar mass calculations before you hand in a final value.

Quick Revision

Formula: K2CO3

Molar Mass: 138.20 g/mol

Key takeaway: count atoms accurately, multiply by atomic masses, and sum only at the end.

Formula Explanation

K2CO3 contains Potassium (K) (2), Carbon (C) (1), Oxygen (O) (3). Add each element contribution to get total molar mass.

Molar Mass = Sum (atomic mass of each element x atom count)

FAQ

The molar mass of K2CO3 is 138.20 g/mol based on atomic masses and atom counts.

Conclusion

Molar Mass of Potassium Carbonate and Molar Mass of K₂CO₃ are now easy to revise with this structured page. You can use this method in exams, lab reports, and daily chemistry practice.