Identify which is the result of a physical rather than
a chemical change?

There are two steps in the usual industrial preparation of acrylic acid, the immediate precursor of several useful plastics. in the first step, calcium carbide and water react to form acetylene and calcium hydroxide: cac2 (s) + 2h2o (g) → c2h2 (g) + caoh2 (s) =δh−414.kj in the second step, acetylene, carbon dioxide and water react to form acrylic acid: 6c2h2 (g) + 3co2 (g) + 4h2o (g) → 5ch2chco2h (g) =δh132.kj calculate the net change in enthalpy for the formation of one mole of acrylic acid from calcium carbide, water and carbon dioxide from these reactions. round your answer to the nearest kj .

Which of the following is an example of how telecommunication devices people do their jobs? a.) a security guard checks the time using a digital watch. b.) a banker does some quick math using a solar calculator. c.) a nurse uses a digital thermometer to take a patient’s temperature. d.) a construction worker reports in to his office using a cell phone.

(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.