How many grams of each of the following substances will dissolve in 100 mL of cold water consult a handbook?

Solubility refers to the maximum amount of a solute that can dissolve in a solvent at a given temperature. When a solution reaches this maximum concentration, it is said to be saturated. Solubility varies widely between different solutes and solvents. It also depends on temperature – most solutes are more soluble at higher temperatures.

This article examines the solubility of various common substances in cold water at room temperature (approximately 20°C or 68°F). Solubility values have been consulted from handbooks and other reference sources. The goal is to determine how many grams of each substance will dissolve in 100 mL of cold water before reaching saturation.

Factors Affecting Solubility

The solubility of a solute in a given solvent depends on several key factors:

Polarity – Polar solvents like water readily dissolve polar solutes like salts and sugars. Nonpolar solutes like fats and oils have very low solubility in water.

Lattice energy – Ionic solids with high lattice energies tend to be less soluble because it takes more energy to break up their crystal lattice structure. Substances with weaker intermolecular forces are more soluble.

Temperature – Solubility usually increases at higher temperatures as added thermal energy helps break apart solute particles from the solvent.

Pressure – For gaseous solutes, increased pressure forces more gas to dissolve in the solvent. Pressure has little effect on solid solutes.

Molecular size – Smaller molecules can more easily fit between solvent molecules, so they tend to have higher solubility. Large, complex molecules tend to have lower solubility.

So in summary, polar, low molecular weight compounds with weak intermolecular forces tend to have the highest solubility in polar solvents like water. Increasing temperature also improves solubility.

Solubility of Common Substances

Here is a look at the solubility values for some common substances in cold water at room temperature:


Salt Solubility (g/100 mL)
Sodium chloride (table salt) 36
Potassium chloride 34
Ammonium chloride 37
Calcium chloride 74
Magnesium chloride 54
Potassium nitrate 13
Sodium acetate 50
Copper(II) sulfate 20

Salts tend to be very soluble in water due to water’s polarity. Smaller ions like chlorides have higher solubility than larger polyatomic ions like sulfates. Overall solubility decreases as lattice energies increase down the periodic table.


Sugar Solubility (g/100 mL)
Glucose 91
Sucrose (table sugar) 204
Maltose 16
Lactose 5

The solubility of sugars varies widely. Sucrose is very soluble due to its small molecular size. Lactose is much less soluble because of its larger, more complex structure.

Other Organic Compounds

Compound Solubility (g/100 mL)
Ethanol Completely miscible
Methanol Completely miscible
Acetone Completely miscible
Toluene 0.05
Benzene 0.18
Hexane 0.0013
Vegetable oil Insoluble

Smaller organic molecules like alcohols and acetone are very soluble in water due to having some polarity. Larger nonpolar molecules like oils and hydrocarbons have extremely poor solubility.


Gases exhibit very low solubility in water at room temperature and atmospheric pressure. For example:

– Oxygen has a solubility of 0.04 g/100 mL

– Nitrogen has a solubility of 0.02 g/100 mL

– Carbon dioxide has a solubility of 0.33 g/100 mL

Solubility increases as gas molecules get smaller and polarity increases.

Factors That Alter Solubility

While the above values reflect solubility in cold water at room temperature, there are several ways to modify solubility:

Temperature – Heating the solvent generally increases solubility because the added energy helps overcome intermolecular forces. Some exceptions exist where solubility decreases with increasing temperature.

Pressure – For gaseous solutes, increased pressure forces more gas into solution. Pressure has negligible effects for solid solutes.

pH – Changing the pH can substantially increase or decrease solubility of ionic compounds by altering chemical equilibria. Acidic conditions enhance solubility of bases, while basic conditions enhance solubility of acids.

Complexation – Adding a complexing agent can capture an insoluble compound in a soluble complex, effectively increasing its solubility. Common complexing agents include EDTA, cyanide, and carbonate.

Particle size – Decreasing particle size increases relative surface area and can significantly increase solubility rates, allowing more of a solid to dissolve over a given time period.

So in practice, chemists have many methods to control solubility beyond relying on innate solubility values.

Kinetics vs. Thermodynamics

It’s important to distinguish between thermodynamic solubility equilibrium and the kinetics of how fast dissolution occurs. Just because a compound has high solubility does not mean it will instantly dissolve. The rate of dissolution can be very slow depending on factors like particle size, stirring/agitation, temperature, and surface area.

However, over long periods, the solubility equilibrium determines the maximum amount that can dissolve once the kinetic limitations are overcome. Most of the values quoted in this article refer to these thermodynamic equilibrium solubilities. But kinetics still plays a key role in how quickly those solubility limits are reached.


In summary, solubility depends on the interplay of solute and solvent properties, temperature, pressure, and other conditions. Smaller, polar, molecular compounds tend to have the highest solubility in water. Ionic compounds are also generally very water soluble. Nonpolar gases and organic compounds exhibit very low aqueous solubility.

Consulting handbooks provides solubility values under standard conditions. But chemists can actively modify solubility by changing temperature, pressure, pH, complexation, or other factors. Distinguishing thermodynamic equilibrium solubility from dissolution kinetics is also important.

This article has aimed to provide solubility values for some common substances in cold water. However, explained the many caveats around these simplified numbers. Understanding and controlling solubility is key for many chemical processes and applications.

Leave a Comment