1. a) Une jeune femme ayant la fibrose kystique a besoin d'un traitement d'oxygène quelques fois par jours. Combien de moles d'oxygène moléculaire
est-ce qu'il y a dans son cylindre de 42.OL?

The answer would be true

Use the universal gas law formula: pv = nrt now, the key word in this problem is stp, so at stp, temperature will always be 0 degrees celsius and pressure will always be 1.0 atm or 760 torr. given something is at stp, we already know the two variables pressure and temperature. the other thing we can find with the given information is moles. to find moles, just divide grams by molar mass of the element. 16.0g / 2(16.00)g/mol = 0.5 moles plug the values in to the equation pv = nrt (1.0 atm)( x ) = (0.5 )(0+273=273k) the r value is just a constant for when we use atm, liters, moles and kelvin. i'm assuming you want your answer in liters, but if you dont just move the decimal 3 to the right in your final answer. so when plugging these numbers in to your calculator and trying to find x, you get 11.20665 liters using significant figures the answer is 11.2 liters

The most likely ph of a highly corrosive acid would be 1. because one is the most acie on the ph scale. the lower the number, the higher the acidity.