This **ppm to molarity calculator** is used for facilitating the **conversion** between two common concentration units: **parts per million (ppm)** and **molarity (M)**.

- A water quality analyst uses the calculator to convert
50 ppmof chlorine to its equivalentmolarity.- A pharmaceutical researcher converts
100 ppmof a drug compound to molarity forprecise dosage calculations.

## PPM to Molarity Calculator

Compound | PPM | Molar Mass (g/mol) | Density (g/mL) | Molarity (M) |
---|---|---|---|---|

NaCl | 500 | 58.44 | 1.0 | 0.00856 |

KCl | 750 | 74.55 | 1.0 | 0.01006 |

CaCl2 | 1000 | 110.98 | 1.0 | 0.00901 |

MgSO4 | 250 | 120.37 | 1.0 | 0.00208 |

NH4NO3 | 100 | 80.04 | 1.0 | 0.00125 |

## PPM to Molarity Formula

**The conversion between ppm and molarity is**:

**Molarity (M) = (ppm * density) / (molar mass * 1000)**

Where:

ppm: concentration in parts per milliondensity: solution density in g/mLmolar mass: compound’s molar mass in g/mol

Consider a **500 ppm solution** of sodium chloride (**NaCl**) in water:

- Density of water: 1 g/mL
- Molar mass of NaCl: 58.44 g/mol

**Molarity = (500 ***1) / (58.44* 1000) = 0.00856 M

## How do you convert ppm to molarity?

Converting ppm to molarity involves these steps:

**Gather information**: Obtain the solution’s ppm, density, and the compound’s molar mass.

**Apply the formula**: Use the PPM to Molarity formula.

**Calculate**: Perform the calculation to determine molarity.

Convert **250 ppm** of glucose (**C6H12O6**) in water to molarity.

**Information:**

Concentration: 250 ppm

Density of water: 1 g/mL

Molar mass of glucose: 180.16 g/mol

**Apply formula:** Molarity = (250 *1) / (180.16* 1000)

**Calculate:** Molarity = **0.00139 M** or **1.39 mM** (millimolar)

## What is 1 ppm equal to?

**1 ppm = 1 mg/L = 1 μg/mL**

In a 1 ppm solution of silver nitrate (**AgNO3**):

- Molar mass of AgNO3: 169.87 g/mol
- Density of water: 1 g/mL

`Molarity = (1 `*1) / (169.87* 1000) = **5.89 x 10^-6 M**

## What is 0.1 molar in ppm?

To convert molarity to ppm, we rearrange the formula:

**ppm = (Molarity ***molar mass* 1000) / density

Convert **0.1 M sodium hydroxide (NaOH)** to ppm.

- Molar mass of NaOH: 40 g/mol
- Density of solution: ~1 g/mL (assuming dilute aqueous solution)

`ppm = (0.1 `*40* 1000) / 1 = **4000 ppm**

## What is the relationship between molarity and ppm?

Molarity and ppm are interconnected concentration units, each with distinct advantages:

**Molarity**: Expresses concentration in moles of solute per liter of solution, useful for stoichiometric calculations.**PPM**: Represents concentration as mass of solute per million mass units of solution, beneficial for trace analysis.

A **0.05 M copper sulfate (CuSO4)** solution:

- Molar mass of CuSO4: 159.61 g/mol
- Density: ~1 g/mL (dilute aqueous solution)

`ppm = (0.05 `*159.61* 1000) / 1 = **7980.5 ppm**

## References

- American Chemical Society. “ACS Guide to Concentration Units.” https://www.acs.org/content/acs/en/education/whatischemistry/concentration-units.html
- National Institute of Standards and Technology. “Concentrations and Units in Chemical Analysis.” https://www.nist.gov/pml/weights-and-measures/concentrations-and-units-chemical-analysis
- Royal Society of Chemistry. “Concentration Calculations.” https://edu.rsc.org/resources/concentration-calculations/1424.article

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