rogue Posted April 10, 2004 Share Posted April 10, 2004 I need some help solving this question... an explaination would be extremly helpful.. thanks Calculate the volume occupied by 0.0950 mol of calcium phosphate at 25oC and 101.3 kPa, given its density at this pressure and temperature is 3.14 g/mL. Link to comment Share on other sites More sharing options...
Dave Posted April 10, 2004 Share Posted April 10, 2004 Convert the mass in mols to standard units (grams), then use the fact that density = mass/volume (i.e. volume = mass*density). Link to comment Share on other sites More sharing options...
Dave Posted April 10, 2004 Share Posted April 10, 2004 Oh, and that volume will then be in ml, not cm3 or some other volume measurement, because you're working from density units that use ml. Link to comment Share on other sites More sharing options...
swansont Posted April 10, 2004 Share Posted April 10, 2004 Oh, and that volume will then be in ml, not cm3[/sup'] or some other volume measurement, because you're working from density units that use ml. A ml is a cm3 Link to comment Share on other sites More sharing options...
Dave Posted April 10, 2004 Share Posted April 10, 2004 Good point. You wouldn't think I was doing a maths degree at university really, would you (my excuse is I haven't looked at anything like that for about 3 years). Link to comment Share on other sites More sharing options...
wolfson Posted April 10, 2004 Share Posted April 10, 2004 You wouldn't think I was doing a maths degree at university really, would you Yes i would students all have there blonde moments, as I forgot my chemistry calculation the other day. Link to comment Share on other sites More sharing options...
wolfson Posted April 10, 2004 Share Posted April 10, 2004 Calculate the volume occupied by 0.0950 mol of calcium phosphate at 25oC and 101.3 kPa, given its density at this pressure and temperature is 3.14 g/mL. Do as dave said for the ml/per gram, then use: V = P / nRT Where V = Volume (L or dm-3) P = Pressure use 1 atm, as your 101.3Kpa = 1 atm n = number of moles which you calculated. R = gas constant of 0.0821 J.K.Mol-1 and T = temperature, that 25 oc = 298.3 K<<<use the K. 2 Link to comment Share on other sites More sharing options...
Hades Posted April 13, 2004 Share Posted April 13, 2004 You wouldn't think I was doing a maths degree at university really' date=' would you [/b'] Yes i would students all have there blonde moments, as I forgot my chemistry calculation the other day. as terrible as an interview i went on the other day where i blanked out the simple formula for molality... MOLALITY of all things..... general chem one for god's sake.. Link to comment Share on other sites More sharing options...
wolfson Posted April 14, 2004 Share Posted April 14, 2004 I know its a nightmare, we all make silly mistakes though. Link to comment Share on other sites More sharing options...
Dave Posted April 14, 2004 Share Posted April 14, 2004 It's just I seem to make quite a few more tha most people Link to comment Share on other sites More sharing options...
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