I have a few homework problems on the Ideal Gas Laws, was wondering if someone could help me out with a few of the problems. 1) Hemoglobin has a molecular mass of 64 500 u. Find the mass (in kg) of 873 molecules of hemoglobin. Here's what I did: (64500 g/mol/6.022x10^23 mol^-1)(873 kg/1000 g)=9.35x10^26 kg but the computer program I use tells me it's wrong...can u find the mistake cause I don't know where it is... 2) A cylindrical glass of water (H2O) has a radius of 6.01 cm and a height of 13.9 cm. The density of water is 1.00 g/cm3. How many moles of water molecules are contained in the glass? Not sure how to work this one out, I was thinking of using V=pi*r^2 and n=N/NA 3) Suppose that a blimp contains 5020 m3 of helium (He) at an absolute pressure of 1.10 x 105 Pa. The temperature of the helium is 276 K. What is the mass (in kg) of the helium in the blimp? Should I use pV=nRT for this problem? 4) A bicycle tire whose volume is 4.1 x 10-4 m3 has a temperature of 283 K and an absolute pressure of 3.76 x 105 Pa. A cyclist brings the pressure up to 7.15 x 105 Pa without changing the temperature or volume. How many moles of air must be pumped into the tire? Does the equation P1V1/T1=P2V2/T2 sound right?