a concentrated solution is one that has
a. no solvent
b. more solute than the solvent
c. a high ratio of solute to solvent
d. a low ratio of solute to solvent
In my opinion this has no clear cut answer from the choices given. A good definition is that a concentrated solution has a RELATIVELY larger amount of solute than solvent and a dilute has a relatively smaller amount of solute than solvent. But the term relatively has a wide range of meanings. Where is the dividing line between concentrated and dilute. In addition, what is considered dilute for one material may be concentrated for another. So a is correct, b and c are correct some of the time, and d is correct depending upon how low the word low is. Another problem is that b and c are vague. when you speak of ratio is that ratio of moles, ratio of grams, or ratio of volumes. As an example, we call commercial grade H2SO4, straight out of the bottle concentrated H2SO4. It actually is 98% H2SO4. That fits b (but many unknowingly think concentrated H2SO4 is "pure" H2SO4 and it isn')t. Concentrated HNO3 is 63% HNO3 and concentration HCl is 37% while concentrated NH3 is 28%. It isn't possible to produce NH3, for example, any stronger than 28%. So how far can be dilute NH3 until we call it dilute. You guess. I don't know the exact dividing line. So if I pick answer a then I don't know of any acid that is concentrated. Take alcohol. If I have pure alcohol than a certainly makes it concentrated but if I make 75% v/v alcohol is that concentrated or not? I think answer a probably is what the author of the question is looking for but I can't be sure of that. Good luck. You can see why specifying the molarity of a material is better than using concentrated and dilute. Having said all of that the terms still are common, even among chemists, especially when they are speaking in general terms.
c. a high ratio of solute to solvent
A concentrated solution is one that has a high ratio of solute to solvent.
To understand why, let's first define solute and solvent. In a solution, the solute is the substance that is being dissolved, while the solvent is the substance in which the solute is dissolved. For example, when salt is dissolved in water, salt is the solute, and water is the solvent.
Now, when we talk about concentration, we are referring to the amount of solute dissolved in a given amount of solvent. A concentrated solution means that there is a large amount of solute dissolved in the solvent.
Considering the answer choices given:
a. "No solvent" - This cannot be the answer because a solution by definition requires both solute and solvent.
b. "More solute than the solvent" - This answer choice implies that there could be enough solute to outweigh the solvent, which is incorrect. Therefore, it is not the correct choice.
c. "A high ratio of solute to solvent" - This answer choice correctly describes a concentrated solution. When the ratio of solute to solvent is high, there is a large amount of solute dissolved in a smaller amount of solvent.
d. "A low ratio of solute to solvent" - This answer choice describes a dilute solution, which is the opposite of a concentrated solution. In a dilute solution, there is a small amount of solute dissolved in a larger amount of solvent.
Therefore, the correct answer is: c. a high ratio of solute to solvent