The gauge on a tank of helium gas says the pressure inside is 2940 psig.
a. what is the actual pressure of the helium gas inside, in pounds per square inch?
b. if a balloon is filled to a volume of 2.00 l and a pressure of 4.50 atmospheres at room temperature (25 oc),
how many moles of helium are in the balloon? assume ideal-gas behavior.

Fugu, also known as puffer fish, is a sushi delicacy that can also be lethal. puffer fish contain a powerful toxin that can kill an adult a few hours after ingestion. sushi chefs who prepare fugu must be specially trained because any contamination of the toxin-free areas of the fish can be deadly. recently this toxin has been put to good use, as scientists have discovered that a purified form of it can treat severe pain in cancer patients. this recent scientific discovery would fall under which area of chemistry? applied biochemistry pure organic chemistry pure physical chemistry applied inorganic chemistry

Select the correct answer. given: 2libr + ba → babr2 + 2li in this chemical reaction, 325 grams of barium (ba) react completely. how many moles of lithium (li) are produced? a. 1.18 mol b. 2.37 mol c. 4.73 mol d. 16.4 mol e. 32.9 mol

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.