Which statement is true of phenolphthalein?
a. it can be used in combustion reactions.
b. it is colorless in the presence of an acid and pink in the presence of a base.
c. it gives you the exact ph of a solution.
d. it is colorless in the presence of a base and pink in the presence of an acid.
e. it is called a decomposition indicator.

Which statement describes the appearance of a temperature-vs.-time graph? a horizontal line shows that the temperature increases at a constant rate over time. a vertical line shows that the temperature decreases at a constant rate over time. horizontal lines where the temperature is constant during phase changes connect upward-sloping lines where the temperature increases. horizontal lines where the temperature increases are connected by upward-sloping lines where the temperature is constant for each phase.

Idon't really understand this can you me and show your work.☺☺[ chemistry b] subject [ electron transfer in lonic bonds]grade( 12)

The rules of engagement (roe) working group is often used to (select all that apply.)