Give the reason for the following; 1. Iodimetric titrations are usually performed in neutral or mildly alkaline (pH 8) to weakly acid solution. 2. Iodine solutions are prepared by dissolving I2 in a concentrated solution of potassium iodide. 3. Iodimetric determination of vitamin C is performed rapidly after preparing vitamin C solution

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.

Why is nh3 classified as a polar molecule

The atom fluorine generally will become stable through the formation of an ionic chemical compound by accepting electron(s) from another atom. this process will fill its outer energy level of electrons.