Question

2) (2 pts) If you dissolve 10.0 g of compound X in 100.0 mL of distilled water, the liquid turns red. The temperature of the liquid stays at 24 °C for 10 minutes. Why would you not want to sell a cold pack made with compound X? 3) Consider a beaker of water that has an initial temperature of 25 °C. When an ionic salt is dissolved in the water, the temperature changes to 5 °C. a. (1 pt) If you were to touch the beaker, what would you feel? b. (1 pt) Is this reaction endothermic or exothermic? C. (2 pt) Is the energy of the products higher or lower than the energy of the reactants? 4) (10 pts) Two competing corporations are submitting data to the US Military to create chemical hot packs. The Military has stipulated that the each hotpack may cost no more than 85 cents and must result in at least a 20 °C rise in temperature when activated. Which of the following companies is the Military going to hire? Corporation Chemical Data Submitted to Military Cost of Chemical Company A 1.5 g of Y results in a 5°C rise in temperature $184.04/ kg Company B 1.0 g of Z results in a 2.5°C rise in temperature $97.13/ kg

Answer 1

0:3. (a) if we touch the beakes, the beaker would feel cold. (b) the reaction is endothermic. (6) energy of products would be higher than reactants. products e native on the sendothermic) energy & reactant 024 (5°c rise in temp. requires 1.5g of v Company Al 20°c size in temp. requires 1.sgx20% - 6.og cost of chemical = $184.04. soc = 6.og Tooo g' *60g =$1.10424 Company .5°c rise in temp. requires = log of z 20% rise in tempo requires= 1.0g x 206 = 8 g of a 2.590 cost of chemical = $97.13 13 x 89 = $0.777 < 85 cents. The millitary is going to hire company B. 10oog