Question

dissolving. increasing both the surface area and stirring will allow sugar to dissolve faster. however, neither will increase the amount of sugar that can dissolve. in other words, neither increases the solubility of sugar. read on to see what increases the amount of sugar that can dissolve.

1. remember that kinetic energy is the energy of motion. heating a solvent results in the molecules having more kinetic energy. they move around more rapidly. as the solvent molecules move more rapidly, they collide with the solute more often and with more force. both factors allow the solute to not only dissolve at a faster rate but allow more of the solute to dissolve.
2. so, back to sweet tea. classic sweet tea involves adding sugar to steaming hot tea. the reasoning is that there is more kinetic energy in hot tea. the rapidly moving hot water molecules collide with the sugar solute more often and with more force. this increases the rate at which the sugar dissolves, and it also increases the amount of sugar that can be dissolved (the solubility). southerners may drink their tea cold, but they add the sugar when its hot. its smart science.

reading evaluation

1. the word substance in paragraph 1 means-

a. the most important or essential part of something.
b. wealth and possessions.
c. the subject matter of a speech.
d. a kind of matter that has consistent properties.

1. a substance dissolved in water is known as a(n)-

a. aqueous solution.
b. liquid solution.
c. heterogeneous mixture.
d. sweet tea mixture.

Explanation:

1. In the context of chemistry (Natural Science - Chemistry subfield), a substance is defined as a kind of matter that has consistent properties. Options A, B, and C do not fit the scientific definition of a substance in this context.
2. In chemistry, when a substance is dissolved in water, it forms an aqueous solution. A liquid solution is too general (it could be a solution in any liquid, not just water). A heterogeneous mixture is not a solution (components are not uniformly distributed). "Sweet tea mixture" is a very specific example and not the general scientific term.

Answer:

1. D. a kind of matter that has consistent properties.
2. A. aqueous solution.