In the early days of automobiles, illumination at night was provided by burning acetylene, c2h2. Though no longer used as auto headlamps, acetylene is still used as a source of light by some cave explorers. The acetylene is (was) prepared in the lamp by the reaction of water with calcium carbide, cac2: cac2(s) + 2h2o(l) ⟶ ca(oh)2(s) + c2h2(g) calculate the standard enthalpy of the reaction. (the δhf° of cac2 is −15. 14 kcal/mol. ).

True or falseaccording to the fifth amendment people cannot be tried for the same exact crime more than once

Which of the following must happen in order for productivity to increase? a. production levels remain unchanged while inputs increase. b. production levels rise while inputs decrease. c. production levels fall while inputs increase.

Apopulation of deer mice was introduced into a desert ecosystem. being dark-colored, the deer mice stood out in the sand and were easy prey for predators. over a few years, the color of the mice changed from dark brown to light brown. what role does natural selection play in this example? a. the change of color camouflaged them, which them hunt better. b. the change of color enabled them to regulate their body temperature. c. the change of color allowed them to hide better from predators. d. the change of color made their bodies tolerant to the harsh desert sand. e. the change of color allowed them to deflect the excessive heat.