A new potential heart medicine, code-named X-281, is being tested by a pharmaceutical company, Pharma-pill. As a research technician at Pharma-pill, you are told that X-281 is a monoprotic weak acid, but because of security concerns, the actual chemical formula must remain top secret. The company is interested in the drug's Ka value because only the dissociated form of the chemical is active in preventing cholesterol buildup in arteries. To find the pKa of X-281, you prepare a 0.078 M test solution of X-281 at 25.0 ∘C. The pH of the solution is determined to be 2.70. What is the pKa of X-281?

11. phosphorus-32 is radioactive and has a half life of 14 days. how much of a 124 mg sample of phosphorus-32 is present after 56 days? a) 7.75 mg b) 15.5 mg c) 31.0 mg d) 62.0 mg

Gasoline has a density of 0.740 g/ml. if you have 328 grams of gasoline, what is the volume in milliliters?

(04.05 hc) analyze the given diagram of the carbon cycle below. an image of carbon cycle is shown. the sun, a cloud, two trees, one on the left and the other on the right, an animal, lake, and a factory are shown in the image. an arrow is shown from the sun towards the left tree marked a. the sun is marked b. there is an arrow from the air above the clouds, marked c, towards the left tree. an arrow from a location close to the ground marked d points towards dead organisms, which is a label under the animal. an arrow marked e points from the right tree straight up to the clouds. an arrow marked f points from the animal straight up to the clouds. an arrow marked g points from the factory towards the air above the clouds, c. there is an arrow pointing from the air to the lake labeled carbonates in water, an arrow pointing down from dead organisms to fossils and fossil fuels, and an arrow from fossils to the factory. part 1: which compound does c represent? part 2: name a process that could release this compound into the air. part 3: explain how the elements that form it are conserved during the carbon cycle. use complete sentences to explain your answer.