38. The following graph shows the historical concentration of atmospheric carbon dioxide in the atmosphere. Carbon dioxide concentrations began increasing in the 1800s as humans started to rely on combustion for energy (carbon dioxide is a product of combustion). The increase in atmospheric carbon dioxide is linked to the increases in global temperatures known as global warming 380 360 340 320 300 280 260 1700 1800 1900 2000 Year Atmospheric carbon dioxide derived from Siple Station ice core measurements and from levels measured at the South Pole, Antarctica (Source: ORNL/CDIAC65) a. What is the total increase in carbon dioxide between 1950 and 2007? b. What is the average yearly increase in carbon dioxide over this period? c. What is the total percentage increase in carbon dioxide over this period? d. What is the average yearly percentage increase in carbon dioxide over this period? CO2 concentration (ppm)

Use the algebraic equation to determine the mass if the volume was 622 mL.  mass (g) = (3.60 g/mL)(volume (mL)) + 11.4 g y= mass (g) m = 3.60 g/mLx= 622 mL b = 11.4 g

Subject: chemistry

A chemistry student must write down in her lab notebook the concentration of a solution of potassium chloride. The concentration of a solution equals the mass of what's dissolved divided by the total volume of the solution. Here's how the student prepared the solution: • The label on the graduated cylinder says: empty weight: 1.55 g • She put some solid potassium chloride into the graduated cylinder and weighed it. With the potassium chloride added, the cylinder weighed 31.436 g. • She added water to the graduated cylinder and dissolved the potassium chloride completely. Then she read the total volume of the solution from the markings on the graduated cylinder. The total volume of the solution was 166.4 mL. What concentration should the student write down in her lab notebook? Be sure your answer has the correct number of significant digits. -1 g.mL x10 × Ś