Answer:
specific heat.
Explanation:
Definition:
The amount of heat required to raise the temperature of one gram of substance by one degree is called specific heat.
Formula:
Q = m. c. ΔT
Q = amount of heat required
m = mass of substance
c = specific heat of substance
ΔT = change in temperature
The substance with greater value of specific heat require more heat to raise the temperature while the substance with lower value will raise its temperature very quickly by absorbing smaller heat.
For example the beach sand gets hot very quickly because of lower specific heat of sand while water is colder than sand because of higher specific heat capacity.
I believe it's D! Hope you can help with my question!
For which of the following activities might you want to hire a chemist?
Answer: D. testing a rock sample for gold content
Which of the following procedures involves a physical change in one of the substances?
Answer: C. separating a salt solution by evaporating the water
Answer:
True
Explanation:
It's true because the pH is a measure of how basic or acid a solution is. In an acidic medium, the pH scales goes from 0 to 7. While in a basic medium goes from 7 to 14. The lower the pH value of the most acid the solution is.
1. The expression pH = -log(molar concentration of hydronium) allow to calculate the pH of a solution.
2. On the other hand, the expression pOH = -log(molar concentration of hydroxide) allow to determine the pOH of a solution.
The values of pH and pOH always obey the following expression:
pH + pOH = 14
Thus if for instance the pH becomes smaller the pOH must become bigger in order to fulfill the equation. Which means that the concentration of hydronium ions is greater than the hydroxide concentration.
For example, in an acidic medium:
if pH= 3, pOH= 11
In this case the molar concentration of hydronium is 0,001M. And the molar concentration of hydroxide ions is just 0,00000000001M.