A 0.495g sample of a hydrocarbon exerts a pressure of 0.799atm in a 0.600L flask at 355K. What is the molar mass of the hydrocarbon? Use R=0.08206 L×atm/mol× K A)30.1 g/mol B) 58.1 g/mol C) 305 g/mol D) 112 g/mol

im not exactly sure but i think its b!

space exploration has led to the development and technological improvement of many everyday items. (if this answer is wrong i will find the right answer) : )

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.