A gas has a density of 1.57 g/L at 40.0 °C and 2.00 atm of pressure. What is the identity of the gas?

c. 75.7

i think that is the right

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.

the electron configuration that you gave me has 16 electrons ergo it has 16 protons ergo it is the element sulfur.

i think its 100.

hope this !