A student wants to determine whether an unknown solid is an ionic compound. He puts some in water and finds that it does not dissolve. He says that this proves the solid is ionic. Which best evaluates the student's reasoning? (2 points) Select one: a. He is incorrect, because water can dissolve ionic solids. b. The test proves nothing, because water dissolves all solids. c. He is correct, because polar liquids cannot dissolve ionic solids. d. The test proves nothing, because it only shows that the solid is a compound.

According to the law of conservation of mass, in a chemical reaction the total starting mass of all the reactants equal the total final mass of all the products. true or false?

The magnitude of the amount of energy released by burning a fuel source, measured in energy per unit mass, is called its fuel value. note that the fuel value is the negative of the isobaric specific heat of combustion for the fuel. if all the energy obtained from burning 1.23 pounds of butane with a fuel value of 10.85 kcal/g is used to heat 128.0 kg of water at an initial temperature of 18.3 °c, what is the final temperature? note that 1 lb = 453.6 g.

The great sandini is a 60.0-kg circus performer who is shot from a cannon (actually a spring gun). you don’t find many men of his caliber, so you him design a new gun. this new gun has a very large spring with a very small mass and a force constant of 1100 n/m that he will compress with a force of 4400 n. the inside of the gun barrel is coated with teflon, so the average friction force will be only 40.0 n during the 4.00 m he moves in the barrel. at what speed will he emerge from the end of the barrel, 2.50 m above his initial rest position?