What is the definition of a primary producer?

What volume of a 0.25 m solution can be made using 0.55 moles of ca(oh)2

What noticeable trend from this graph might be used to make a conclusion?

Which statement best describes how the loudness of the sound affects the high-pressure region created by the sound wave? a. a louder sound has no effect on the pressure created. b. a louder sound means a high-pressure region that is higher. c. a louder sound means a high-pressure region that is not as high.