The U. S. Public Health Service recommends the fluoridation of water as a means for preventing tooth decay. The recommended concentration is 1.0 mg F per liter. The presence of calcium ions in hard water can precipitate the added fluoride. What m molarity of calcium is at the USPHS recommended level? (Ksp for CaF2 is 4.0 × 10-11.)

Given sno2 + 2h2 - sn + 2h20 tin oxide reacts with hydrogen to produce tin and water. how many moles of sno2 are needed to produce 500.0 grams of sn?

Acalorimeter is to be calibrated: 51.203 g of water at 55.2 degree c is added to a calorimeter containing 49.783 g of water at 23.5c. after stirring and waiting for the system to equilibrate, the final temperature reached is 37.6 degree c. specific heat capacity of water (s = 4.18 j/g∙degree c). calculate the calorimeter constant. (smδt)warm water = -[(smδt)cold water + (calorimeterδtcold water)]

How is the way a mixture is combined different from how a compound is combined?