Calcium hydroxide, which reacts with carbon dioxide to form calcium carbonate, was used by the ancient romans as mortar in stone structures. the reaction for this process is

ca(oh)2(s) + co2(g) --> caco3(s) + h2o(g) ; δh = -69.1 kj

what is the enthalpy change if 3.8 mol of calcium carbonate is formed?

(a) -18 kj
(b) -69 kj
(c) -73 kj
(d) -260 kj

An empty fuel tank can still contain and therefore can be even more dangerous than one full of liquid fuel.

Select the correct value for the indicated bond angle in each of the compounds. o−o−oo−o−o angle of o3 90° 109.5° < 109.5° 120° < 120° 180° f−b−ff−b−f angle of bf3 180° < 109.5° < 120° 120° 109.5° 90° f−o−ff−o−f angle of of2 < 120° 120° 90° 109.5° 180° < 109.5° cl−be−clcl−be−cl angle of becl2 90° 109.5° 180° 120° < 109.5° < 120° f−p−ff−p−f angle of pf3 90° 109.5° < 109.5° 180° 120° < 120° h−c−hh−c−h angle of ch4 90° < 109.5° 180° 120° < 120° 109.5°

Acandle’s wick is the fabric string that holds the flame, and it burns down at a constant slow pace when the candle is lit. the wick is usually surrounded by wax. which is the most important property of covalent compounds that makes them useful for making candle wax? a low boiling point a low melting point a high boiling point a high melting point