PPM to Molarity Calculator
Convert between parts per million (PPM) and molarity for chemical solutions
Convert PPM and Molarity
Parts per million concentration
Molecular weight in g/mol
Advanced: Solvent Density (Optional)
Solvent density in g/mL (default: 1.0 for water at room temperature)
Quick Select Common Substances
Conversion Results
Calculation Details
Formula: Molarity = PPM(mg/L) ÷ (Molar Mass × 1000 mg/g)
Calculation: Molarity = 0 mg/L ÷ (0 g/mol × 1000 mg/g) = 0.000e+0 M
Assumption: Dilute aqueous solution at room temperature
PPM definition: mg of solute per L of solution (for water-based solutions)
Concentration level:
Concentration Analysis
Example Calculation
Seawater Salinity Example
Problem: Seawater contains approximately 35,000 mg/L of salt (NaCl). What is the molarity?
Given: PPM = 35,000 mg/L, Molar mass of NaCl = 58.44 g/mol
Find: Molarity in mol/L
Step-by-Step Solution
Step 1: Apply the formula: Molarity = PPM ÷ (Molar Mass × 1000)
Step 2: Calculate: Molarity = 35,000 mg/L ÷ (58.44 g/mol × 1000 mg/g)
Step 3: Simplify: Molarity = 35,000 ÷ 58,440 = 0.599 mol/L
Step 4: Compare to drinking water limit (20 mg/L): 35,000 ÷ 20 = 1,750 times saltier
Answer: Seawater has a salinity of 0.599 M NaCl
Concentration Scale
Key Formulas
PPM to Molarity
M = PPM/(MW×1000)
PPM in mg/L, MW in g/mol
Molarity to PPM
PPM = M × MW × 1000
Result in mg/L
PPM Definition
1 ppm = 1 mg/L
For dilute aqueous solutions
Conversion Factor
1000 mg = 1 g
Essential for unit conversion
PPM Applications
Understanding PPM and Molarity
What is PPM?
Parts per million (PPM) is a concentration measurement that expresses the amount of one substance in another. For dilute aqueous solutions, 1 PPM typically equals 1 mg of solute per liter of solution (mg/L).
What is Molarity?
Molarity (M) is the number of moles of solute dissolved in one liter of solution. It's the most common way to express concentration in chemistry because it relates directly to the number of molecules or ions in solution.
Why Convert Between Them?
- •Environmental analysis often uses PPM
- •Chemical reactions require molarity
- •Quality control specifications vary
- •Regulatory compliance requirements
Conversion Principles
PPM Definition
1 ppm = 1 mg solute per 1 L solution
Valid for dilute aqueous solutions
Molarity Definition
1 M = 1 mol solute per 1 L solution
Based on Avogadro's number
Key Relationship
Molar mass bridges the conversion
Links mass (PPM) to moles (Molarity)
Important Assumptions
- •Solution density ≈ 1 g/mL (water-like)
- •Room temperature conditions
- •Dilute solution (PPM less than 10,000)