No, grape juice is not a pure substance, because it is made up of more than one element or compound.
In the article that follows, we’ll explain what a pure substance is, and why it is that grape juice (even white grape juice) doesn’t qualify.
Why Is Grape Juice A Pure Substance (Or Not?)
What Is A Pure Substance?
Let’s talk about what a pure substance is.
A pure substance is one that is made up of only one kind of building block.
The building block can be an element, or it can be a compound.
If the substance has more than one element that is not bonded to the other substances, or more than one compound not bonded to the others, it is not a pure substance.
A good example of a pure substance that is made up of an element is gold. Pure silver, lead, and copper also qualify as pure substances.
A good example of a pure substance that is made up of a compound is sugar.
Salt, distilled water, and carbon dioxide also qualify as pure substances.
What Is Grape Juice?
Grape juice, perhaps more than other juices, has been extensively studied, probably because the juice of grapes is a major component in the creation of valuable wine.
For our purposes, we don’t have to dive terribly deep into wine’s chemical composition, even though it might be really interesting.
Grade juice is composed of water, plus sugars, acids (like tartaric, malic, and citric), phenolic compounds, minerals, and more. (source)
Is Grape Juice A Pure Substance?
Nope, grape juice is not a pure substance.
Grape juice will definitely vary as far as levels of sugar, acids, minerals, and various compounds.
In the end, all that matters is that there is more than one compound or element in the substance.
Grape juice is water plus a bunch of stuff.
That’s pretty much the end of the inquiry as it relates to the analysis of the pure substance question.
Is White Grape Juice A Pure Substance?
No, white grape juice is not a pure substance.
White grape juice might look more like water than it does juice.
But even though it is clear, white grape juice is made up of multiple substances (water, sugars, and more).
We don’t even have to get in deep as to how white grape juice is different from other kinds.
Since there is more than one element or compound in the material it cannot be considered a pure substance.
Is Grape Juice A Mixture?
Yes, grape juice would be considered a mixture.
A mixture is a material that is made up of multiple substances, where the substances are not bonded to each other.
Because of the lack of bonds, the substances can be separated without a chemical reaction.
A mixture may include elements, molecules, and compounds.
Grape juice is made up of water, with sugars, acids, and other compounds.
The sugars and acids and compounds are not bonded to the water molecules.
The sugars, acids, and compounds are also not bonded to each other.
They can be separated without a chemical reaction.
This is why grape juice is a mixture.
Is Grape Juice A Heterogeneous Or Homogeneous Mixture?
In general, the grape juice (of all kinds) that you come across is going to be a homogeneous mixture.
A homogeneous mixture is one that is chemically and usually physically consistent throughout the material.
A heterogeneous mixture is one that is not chemically consistent throughout the mixture.
Commercially prepared and sold grape juice is pressed and then filtered.
In most cases, the product you receive is chemically and physically the same throughout the material, because this quality of product is what is required for a company to succeed.
However, grapes vary from plant to plant.
In the case of pressing your own juice, until the juice has a chance to mix up and settle after being pressed, and certainly before being filtered, the material is going to be quite heterogeneous.
This means that certain areas might have more sugars (or less), more or less of the compounds and minerals, etc.
But assuming the juice is in a more finished state, we’ll call is homogeneous.
Is Grape Juice A Compound?
No, grape juice is not a compound.
A compound is created when two different substances (elements, molecules, or compounds) form bonds to each other.
In the case of grape juice, the parts that make up the material are not all bonded to each other.
Grape juice certainly contains several compounds (such as the various sugars).
But this does not make the juice itself a compound.
Is Grape Juice An Element?
No, grape juice is not an element.
An element is a substance which cannot be broken down or apart into simpler substances.
Water, for example, is not an element because it can be broken apart into oxygen and hydrogen.
Gold, on the other hand, is an element, because it cannot be broken down or apart into any simpler substance.
Grape juice can be broken down into many, many different kinds of substances, it contains multiple compounds.
This is why grape juice is not an element.