Solubility of Potassium Bromide (KBr) at 23 °C Calculator
Calculate KBr Solubility at 23°C
Enter the mass of water in grams.
Enter the mass of Potassium Bromide added in grams.
Calculations are based on 23 °C.
What is the Solubility of Potassium Bromide at 23 °C?
The Solubility of Potassium Bromide at 23 °C refers to the maximum amount of potassium bromide (KBr), a white crystalline salt, that can dissolve in a given amount of solvent (usually water) at a specific temperature of 23 degrees Celsius to form a saturated solution. At 23 °C, the solubility of KBr in water is approximately 66.9 grams per 100 grams of water (g/100g H2O). This means that at this temperature, 100 grams of water can dissolve up to 66.9 grams of KBr.
Understanding the Solubility of Potassium Bromide at 23 °C is crucial for chemists, pharmacists, and students working with solutions of KBr. If you add more KBr than this limit to 100g of water at 23°C, the excess will not dissolve and will remain as a solid precipitate, assuming no supersaturation occurs.
Common misconceptions include believing that any amount of salt will dissolve or that temperature doesn’t significantly affect solubility (it does, as shown in the chart below).
Solubility of Potassium Bromide Formula and Explanation
While there isn’t a single formula to derive the solubility at a *specific* temperature like 23°C from first principles easily (it’s experimentally determined), we use the experimentally found value for calculations. The solubility of KBr at 23°C is taken as S23 = 66.9 g/100g H2O.
If you have ‘W’ grams of water and add ‘K’ grams of KBr at 23°C:
- Maximum KBr that can dissolve (Mdissolved): Mdissolved = (W / 100) * S23 = (W / 100) * 66.9 g
- Amount of KBr dissolved: If K ≤ Mdissolved, then all K dissolves. If K > Mdissolved, then Mdissolved grams dissolve.
- Undissolved KBr: If K > Mdissolved, Undissolved = K – Mdissolved. Otherwise, it’s 0.
- Concentration: If K ≤ Mdissolved, Concentration = (K / W) * 100 g/100g H2O. If K > Mdissolved, the solution is saturated, and Concentration = S23 = 66.9 g/100g H2O.
Variables Table
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| ST | Solubility at temperature T | g/100g H2O | 50-80 (0-40°C) |
| S23 | Solubility at 23°C | g/100g H2O | 66.9 (fixed) |
| W | Mass of Water | g | 1 – 1000+ |
| K | Mass of KBr added | g | 1 – 1000+ |
| Mdissolved | Maximum KBr that can dissolve | g | Calculated |
Solubility of KBr with Temperature
The solubility of potassium bromide, like most solid solutes in liquid solvents, is dependent on temperature. Generally, solubility increases with temperature.
| Temperature (°C) | Solubility of KBr (g/100g H2O) |
|---|---|
| 0 | 53.5 |
| 10 | 59.5 |
| 20 | 65.2 |
| 23 | 66.9 |
| 30 | 70.6 |
| 40 | 75.5 |
| 50 | 80.2 |
| 60 | 85.5 |
Practical Examples
Let’s look at how the Solubility of Potassium Bromide at 23 °C works in practice.
Example 1: Undersaturated Solution
You add 30g of KBr to 50g of water at 23°C.
- Water = 50g, KBr added = 30g, Temp = 23°C
- Max KBr that can dissolve = (50/100) * 66.9 = 33.45g
- Since 30g (added) < 33.45g (max), all 30g will dissolve.
- Undissolved KBr = 0g
- Concentration = (30/50) * 100 = 60 g/100g H2O (Unsaturated)
Example 2: Saturated Solution with Excess Solid
You add 80g of KBr to 100g of water at 23°C.
- Water = 100g, KBr added = 80g, Temp = 23°C
- Max KBr that can dissolve = (100/100) * 66.9 = 66.9g
- Since 80g (added) > 66.9g (max), only 66.9g will dissolve.
- Undissolved KBr = 80 – 66.9 = 13.1g
- Concentration = 66.9 g/100g H2O (Saturated)
How to Use This Solubility of Potassium Bromide at 23 °C Calculator
- Enter Amount of Water: Input the mass of water you are using in grams.
- Enter Amount of KBr Added: Input the mass of KBr you are adding to the water in grams.
- Observe Temperature: The calculator is fixed at 23°C.
- Click Calculate: The results will show the maximum KBr that can dissolve, any undissolved amount, the solution concentration, and saturation status at 23°C.
- Read Results: The primary result shows how much KBr actually dissolved. Intermediate results give more detail.
- View Chart: The bar chart below the results visually compares the amount added, dissolved, and undissolved.
Key Factors That Affect Solubility Results
- Temperature: This is the most significant factor. The Solubility of Potassium Bromide at 23 °C is a specific value, but at other temperatures, it’s different. Higher temperatures generally mean higher solubility for KBr.
- Amount of Solvent (Water): More water can dissolve more KBr at the same temperature. The maximum amount dissolved is directly proportional to the amount of water.
- Amount of Solute (KBr) Added: Adding more KBr than can dissolve at 23°C will result in a saturated solution with undissolved solid.
- Purity of KBr and Water: Impurities can slightly alter the solubility.
- Pressure: For solids like KBr dissolving in liquids, pressure has a negligible effect on solubility.
- Particle Size of KBr: Finer particles dissolve faster, but the final amount dissolved (solubility) at equilibrium is the same regardless of initial particle size, given enough time.
Frequently Asked Questions (FAQ)
A: Since the density of water is close to 1 g/ml around room temperature, 100ml of water is approximately 100g. So, about 66.9 grams of KBr will dissolve in 100ml of water at 23 °C.
A: Yes, the solubility of KBr increases with temperature. If you have undissolved KBr at 23°C and heat the mixture, more will likely dissolve.
A: As the solution cools, the solubility decreases. Excess KBr that was dissolved at the higher temperature may precipitate out as solid crystals, unless supersaturation occurs.
A: No, solubility is specific to the solute-solvent pair and temperature. KBr is very soluble in water but much less so in alcohols, for example.
A: It’s a commonly cited value, but slight variations can be found in different data sources due to experimental conditions. It’s a very good approximation for Solubility of Potassium Bromide at 23 °C.
A: A saturated solution at 23°C contains the maximum amount of KBr (66.9g per 100g water) that can dissolve at that temperature in equilibrium with undissolved solid (if present).
A: Yes, by carefully cooling a saturated solution made at a higher temperature without disturbance, you might achieve a supersaturated solution, containing more dissolved KBr than the equilibrium amount at 23°C. These solutions are unstable.
A: Solubility is often expressed as mass of solute per mass of solvent (or volume of solvent), especially when showing temperature dependence, as it’s independent of volume changes with temperature for the solvent mass. Molarity can also be used but requires density information for volume-based calculations.
Related Tools and Internal Resources
- Molarity Calculator: Calculate the molarity of solutions.
- Solution Dilution Calculator: Calculate how to dilute a stock solution.
- Temperature Conversion: Convert between Celsius, Fahrenheit, and Kelvin.
- Chemical Compound Database: Find properties of other chemical compounds.
- Lab Solution Preparation Guide: Learn more about preparing solutions.
- Potassium Bromide Properties: Detailed information about KBr.