For the cold pack shown below, the temperature on the outside surface has dropped considerably from its initial temperature of 25 °C. Which of the following provides the best explanation for this temperature decrease? A. The cold pack is releasing cold to the surroundings.
B. Ice is beginning to form on the outside of the bag, lowering its temperature.
C. Energy is traveling out of the bag into the surroundings, making the bag colder.
D. The thermometer is measuring the temperature of the surroundings, which is losing energy.

Why does his teacher ask him to balance the equation by including the correct coefficient

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 .

The volume of an unknown substance in a sealed glass jar is 50 milliliters. the volume of the jar is 200 milliliters. which state of matter could the substance be?