Blood is a mixture. it contains multiple substances that are not chemically bonded to each other, and those substances can be separated from each other without a chemical reaction.
Want to learn more about what a mixture is and why blood qualifies? Check out the article that follows.
Is Blood a Mixture? (Why or Why Not?)
First, let’s talk about what a mixture is.
Scientifically speaking, a mixture is a substance that is made up of more than one substance.
Those substances do not bond to each other chemically, and they can be separated without breaking chemical bonds.
Next, let’s talk about what blood is.
Blood is made up of liquids and solids.
The liquid part (which is what we think of when we think of blood, like when we cut ourselves) is composed of water, salts, and protein.
The solid part is made up of red blood cells, white blood cells, and platelets. (source)
The reason that blood is considered a mixture is that it is made up of multiple substances that are not chemically bonded to each other.
For example, the plasma can pretty easily be separated from the red blood cells, white blood cells, and platelets.
Harvesting platelets is as simple as drawing blood, and then spinning the collected blood to separate the liquid from the platelets and blood cells.
The liquid and platelets can be collected so that the remainder (cells) is returned to the donor.
No chemical reaction is required, and no chemical bonds need to be broken to remove some of the components of blood from the others.
While it might seem like a strange comparison, analyzing blood as a mixture is a lot like analyzing pizza as a mixture.
Like blood, pizza has a base crust (which could be a homogeneous mixture).
The pizza is then mixed up with a bunch of sauce and toppings, and the amounts of concentrations vary wildly.
Is Blood a Homogeneous Mixture?
No, blood is a homogeneous mixture.
A homogeneous mixture is a mixture that is consistent in composition throughout the body.
While blood seems like it would be homogeneous (after all, the blood is always the same color when it comes out of your body, at a chemical level this is not the case.
The amounts and concentration of red blood cells, white blood cells, and even other elements of the plasma can change within the body at any given time, depending on what the body needs.
Blood is a heterogeneous mixture, meaning that the mixture is not consistent throughout.
Is Blood a Compound?
No, blood is not a compound.
A compound is a material where the elements or substances that make up the compound are chemically bound to each other.
To separate those substances, the chemical bond must be broken.
Blood is made up of multiple substances that can easily be separated, as they are not chemically bonded to each other.
Thus, blood is not a compound.
Is Blood a Mixture or a Solution?
Blood is a mixture, and some of blood is a solution (but not all).
A solution is made when one substance dissolves into another substance.
In the case of blood, the liquid that the red blood cells, white blood cells, and platelets travel around in is full of dissolved chemicals, like salts and sugars.
However, the definition of a solution as we understand it could not extend to the cells and platelets that are also found in blood.
Is Blood Plasma Just Water?
No, blood plasma (without the cells and platelets) is not just water.
While it is mostly water, it is not all water. In addition to water, plasma is made up of salts, fats, proteins, hormones, clotting factors, and more.
Is Blood a Suspension?
Yes, blood is a suspension.
A suspension is a heterogeneous mixture in which the added particles do not dissolve, but get held within the liquid.
They basically just float around freely.
If left undisturbed (meaning the liquid and particles in it are not pumped or moved), the particles eventually sink downward with gravity.
A good example of this is how dirt or sand mixed up in water eventually settles at the bottom of the container if you leave it alone long enough.
If the particles were so small that they never settled, you’d have what is called a colloid, and not a suspension.
Is Blood considered an Element?
No, chemically speaking, blood is not considered an element.
An element is a substance which cannot be broken down into simpler substances by ordinary chemical processes.
Blood is composed of multiple substances, and multiple elements, such as oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus.
Blood can be broken down into many simpler substances. Thus, it is not an element.
Interested in learning more about pure substances and mixtures? Or whether materials like bronze, copper, milk, vinegar, and honey are considered pure substances or mixtures?
Check out our Science Page for our latest posts as we dig deeper and learn more about the world we live on.