So I'm new to the dimensional analysis world and I'm little confused and the answers I'm getting are not convincing :(

if the concentration of hemoglobin in a 5ml sample of blood is 34 g/dL. and red blood cells are 31.45 hemoglobin, what is the mass of red blood cells in the sample?

So.. any thoughts on how to do it?

Thank you so much


1 Answer 1


It doesn't seem like you need the 31.45 hemoglobin number (which is good because no units are given:

5ml * 34g rbc /dL * 1 dL/ 100 ml = 1.7 g rbc

would fall out from unit analysis

  • $\begingroup$ Thank you!! hemoglobin's unit is percentage. 31.45% so should i just multiply your number it with that? $\endgroup$
    – user6058
    Mar 17, 2014 at 20:07
  • $\begingroup$ Shigeta's equation should have used "hgb" instead of "rbc". To turn 1.7g hgb into rbc, you multiply it by the .3145 hgb/rbc value. Note the dimensional units work out. $\endgroup$
    – mgkrebbs
    Mar 17, 2014 at 20:13

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.