please answer all the questions

Which of the following gases would have the greatest density at STP? Question 3 Calculate the density of methane gas (CH4, units of g/L) at 290K and 120kPa. Note: Canvas will not allow you to enter units, please enter only your numerical value. Water can be broken down into hydrogen and oxygen gas through electrolysis according to the reaction below: 2H2O(D)2H2(g)+O2(g) The resulting hydrogen and oxygen gas mixture produces a total pressure of 210kPa. What is the partial pressure of hydrogen in this gas mixture? 140kPa 50kPa 70kPa 105kPa At extremely high pressures (>>100atm), measured pressures are higher than those predicted by the ideal gas law. Why is this? The volume occupied by the gas molecules cannot be neglected The intermolecular forces acting between the gases cannot be neglected. Both would contribute to higher pressures than those predicted by the ideal gas law. Neither would contribute to higher pressures than predicted by the ideal gas law