Question

1. One cause of acid rain is the combustion of hydrocarbons. This particular mechanism leads to the presence of carbonic acid in rain. Frank, or The Artist formerly known as The Chemist, lives in a city where this type of acid rain is abnormally common. One day he decides to perform an experiment in order to determine the concentration of carbonic acid in his city's rain. He considers the possibility of simply collecting some rain in a beaker and measuring the pH, but he decides this approach is too easy and boring. Instead, he dissolves 24.18 grams of iron (III) nitrate in a beaker containing 100.0 mL of DI water and 50.0 mL of collected rainwater. He notes that the thermometer in his kitchen reads 25 °C. When Frank measures the pH of this mixture his meter reads 1.98. a. What is the original concentration of carbonic acid in the rain (mg/mL)? b. Frank is feeling chaotic, so he adds 150.0 mL of 6.00 M nitric acid to the solution. What is the pH of the new mixture? C. Frank happens to have the ability to perform combustion analysis in his garage, so he decides to determine the identity of the hydrocarbon primarily responsible for the acid rain. He travels to the nearby industrial park and covertly collects a 55.5 g sample from a bucket inconspicuously labelled "Hydrocarbons for Combusting". During the combustion analysis, Frank collects 176.0 g of carbon dioxide and 66.9 g of water. What is the empirical formula of the substance Frank collected?

Answer 1