When powdered milk is added to water, is it a coarse suspension, true solution, or colliodal dispersion? What about baking soda in water?
Milk is a colloidal dispersion of submicron-size "micelles" of protein and calcium. This is true whether the milk is fresh or reconstituted from powder.
Baking soda dissolves in water to form a true solution.
Would non-dairy creamer also be a colloidal dispersion if it is put in water?
When powdered milk is added to water, it forms a colloid. A colloid is a mixture in which the particles are dispersed throughout the water, but they are not dissolved. In the case of powdered milk, the particles do not completely dissolve in water but remain suspended, creating a milky appearance.
On the other hand, when baking soda is added to water, it forms a true solution. A true solution is a homogeneous mixture in which the solute (baking soda) completely dissolves in the solvent (water), resulting in a transparent solution. In this case, the baking soda particles dissolve at a molecular level, becoming invisible in the water.
To determine whether powdered milk in water forms a coarse suspension, true solution, or colloidal dispersion, we need to understand the definitions of these terms.
1. Coarse Suspension: A coarse suspension refers to a mixture in which solid particles are visible and do not dissolve but instead settle at the bottom of the container due to gravity. It usually appears cloudy or opaque.
2. True Solution: A true solution is a homogenous mixture where the solute (in this case, powdered milk) gets uniformly distributed at a molecular level throughout the solvent (water). The solute particles are typically smaller than 1 nanometer, and the solution is transparent and homogeneous.
3. Colloidal Dispersion: A colloidal dispersion, also known as a colloid, is a heterogeneous mixture where particles of the solute (in this case, powdered milk) are dispersed in a medium (water) to form a stable suspension. The particle size is typically between 1 nanometer and 1 micrometer. The colloidal dispersion appears translucent or milky.
Now, considering powdered milk in water:
When powdered milk is added to water, it forms a colloidal dispersion. The proteins, fats, and other substances in powdered milk are dispersed throughout the water, resulting in a stable and milky suspension. Since the particle size of the components in powdered milk is within the colloidal range, they do not dissolve at a molecular level like in a true solution.
Regarding baking soda in water:
When baking soda (sodium bicarbonate) is added to water, it undergoes a chemical reaction and dissociates into sodium ions (Na+) and bicarbonate ions (HCO3-). The resulting solution is a true solution as the sodium and bicarbonate ions get uniformly distributed in the water at a molecular level.
In summary:
Powdered milk in water forms a colloidal dispersion.
Baking soda in water forms a true solution.