The chemical equation below shows the combustion of propane (c3h8). C3h8 + 5o2 right arrow. 3co2 + 4h2o the molar mass of oxygen gas (o2) is 32. 00 g/mol. The molar mass of c3h8 is 44. 1 g/mol. What mass of o2, in grams, is required to completely react with 0. 025 g c3h8? 0. 018 0. 034 0. 045 0. 91.

When amy exercises in her fitness center for 1 hr she burns a total of 475 calories. if she burns 9 calories a minute jogging on the treadmill and then burns 6.5 calories a minute pedaling on the stationary bicycle how many minutes of the hour does she spend exercising on the bicycle?

In the image, layer a is the topmost layer. layer c contains fossils from the precambrian era. layer b contains dinosaur fossils, and layer a contains fossils of mammals. which two statements are supported by this evidence? 1. mammals lived before the precambrian era. 2. dinosaurs and mammals existed in the precambrian era. 3. dinosaurs evolved after precambrian organisms. 4. precambrian organisms evolved after dinosaurs. 5. precambrian organisms were the first life-forms to become fossilized, according to this sample.

In this food web, which group would increase in number if snakes were eliminated? a. producers b. decomposers c. primary consumers d. secondary consumers e. tertiary consumers