If a 1.85 g mass of zinc produces 475 ml of gas and your balloon weighs 0.590 g and the room temperature is 23.5°c. calculate the amount of zinc needed to produce enough gas to get your balloon airborne by adding 1 ml to the required balloon volume so that its density is less than that of the surrounding air. (hint: complete balloon volume calculation as you did in question 2 above)

What is the total reduction potential of a cell in which potassium (k) is reduced and copper (cu) is oxidized? a. 2.59 v b. 3.27 v c. -3.27 v d.-2.59 v

Two nitro no2 groups are chemically bonded to a patch of surface. they can't move to another location on the surface, but they can rotate (see sketch at right). it turns out that the amount of rotational kinetic energy each no2 group can have is required to be a multiple of ε, where =ε×1.010−24 j. in other words, each no2 group could have ε of rotational kinetic energy, or 2ε, or 3ε, and so forth — but it cannot have just any old amount of rotational kinetic energy. suppose the total rotational kinetic energy in this system is initially known to be 32ε. then, some heat is removed from the system, and the total rotational kinetic energy falls to 18ε. calculate the change in entropy. round your answer to 3 significant digits, and be sure it has the correct unit symbol.

Complete each row of the table below by filling in the missing prefix or missing exponent.