MolarMass logo
Molar Mass Lab/Molar mass for Na2S2O3
Salt

Molar Mass of Sodium Thiosulfate (Na2S2O3)

Molar Mass of Sodium Thiosulfate makes it easier to move between measured grams and moles in classroom precipitation problems. Molar Mass of Na₂S₂O₃ is 158.10 g/mol, based on 3 element types, with S 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 page.

Molar Mass of Sodium Thiosulfate is:

158.10 g/mol

Molar Mass of Na₂S₂O₃ equals 158.10 g/mol, so 158.10 grams is one mole.

Element Breakdown Table

ElementCountAtomic massCalculationContribution
Sodium (Na)222.992 x 22.9945.98 g/mol
Sulfur (S)232.062 x 32.0664.12 g/mol
Oxygen (O)316.003 x 16.0048.00 g/mol
Final molar mass
45.980 + 64.120 + 48.000
158.10 g/mol

Computing Molar Mass of Sodium Thiosulfate Step by Step

Molar Mass of Sodium Thiosulfate: Step-by-Step Calculation

1. Identify Element Counts

Read Na2S2O3 and list how many atoms of each element are present:

  1. 2 atoms of Sodium (Na)
  2. 2 atoms of Sulfur (S)
  3. 3 atoms of Oxygen (O)

2. Determine Atomic Masses

Look up each element mass from the periodic table:

  1. Sodium (Na) ~= 22.990 g/mol
  2. Sulfur (S) ~= 32.060 g/mol
  3. Oxygen (O) ~= 15.999 g/mol

3. Multiply Atomic Mass by Quantity

Multiply atom count by atomic mass for each element:

  • Sodium (Na): 2 x 22.990 = 45.980 g/mol
  • Sulfur (S): 2 x 32.060 = 64.120 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 22.990 + 2 x 32.060 + 3 x 15.999)

Molar Mass = 45.980 + 64.120 + 48.000

Molar Mass = 158.100 g/mol

Final rounded value shown on this page: 158.10 g/mol.

Visual Calculation Chart

ElementCountMassCount x massContribution
Sodium (Na)222.9902 x 22.990= 45.980
Sulfur (S)232.0602 x 32.060= 64.120
Oxygen (O)315.9993 x 15.999= 48.000
Final molar mass
45.980 + 64.120 + 48.000
= 158.100

Easy Way to Remember

Easy way to remember Molar Mass of Sodium Thiosulfate

  • Molar Mass of Sodium Thiosulfate: 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.

Use this checklist with molar mass guide whenever you want a quick confidence check.

Sample Reactions

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

Do You Know?

Sodium Thiosulfate contains 3 element types: Na, S, O.

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

In Na₂S₂O₃, O appears with the highest atom count.

Its molar mass is 158.10 g/mol, which is used directly in gram-to-mole conversions.

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

Why This Compound Matters

Sodium Thiosulfate 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 Sodium Sulfate (Na2SO4) and Sodium Hydrogen Sulfate (NaHSO4).

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 Na₂S₂O₃ and miscounting atoms.
  • Rounding atomic masses too early before finishing all multiplication steps.
  • Mixing up S element contribution with total molar mass.
  • Reporting a value without units; final answer should be in g/mol for Sodium Thiosulfate.

Quick Revision

Formula: Na2S2O3

Molar Mass: 158.10 g/mol

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

Formula Explanation

Na2S2O3 contains Sodium (Na) (2), Sulfur (S) (2), 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 Na2S2O3 is 158.10 g/mol based on atomic masses and atom counts.

Conclusion

Molar Mass of Sodium Thiosulfate and Molar Mass of Na₂S₂O₃ are now easy to revise with this structured page. You can use this method in exams, lab reports, and daily chemistry practice.