How much heat energy, in kilojoules, is required to convert 32.0 g of ice at - 18.0 degrees * C to water at 25.0^ C^ prime ? Express your answer to three significant figures and include the appropriate units.

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.

Which is an example of the practical pursuit of alchemy? a. forming perfect substances. b. transforming base metals. c. developing metalworking techniques. d. linking spiritual characteristics with material substances.

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?