What is the volume of an oxygen tank if it contains 12 moles of oxygen at 273 k under 75 kpa?

Ibeg i need 20. a reaction produces 4.93 l of oxygen, but was supposed to produce 1 mol of oxygen. what is the percent yield?

The human eye contains a molecule called 11-cis-retinal that changes shape when struck with light of sufficient energy. the change in shape triggers a series of events that results in an electrical signal being sent to the brain that results in vision. the minimum energy required to change the conformation of 11-cis-retinal within the eye is about 164 kj/mol.

How many moles of lead are in 1.50 x 10^12 atoms of lead? could you explain the answer as well and not just give it to me i am refreshing for finals and i need to know how to do it