Suppose a 14-gram sample of iron is heated from 20.0°C to 25.0°C. The specific heat of iron is 0.11 cal/g°C. How much heat energy was absorbed by the iron?

38.5 cal
7.7 cal
636 cal
69.3 cal

How can you improve the percent yield of copper in this lab? check all possible strategies that will you do so. measure reactants precisely. stir to the reaction take place. chill the reactants before combining them. wait patiently until the reaction completes. make sure to recover as much copper as possible.