[hightime]

Well im encountering some probelms with a question im doing.

Q:The hemoglobin in red blood cells carries oxygen to body tissues. What amount of hemoglobin is in 25.0 mL of a hemoglobin soloution with a concentration of 1.90 x 10-3mol/L

a: v=25.0
    c=1.90x10^3 mol/L

n=c x v
  =1.90x10^3 mol x 25.0


now my question how the heck do i put this in my calculator  im thinking im doing something wrong with the 3 thing. this is because ive been getting the right answer whenever it isnt giving me the 3 thing. The correct answer in my book is 4.75 x 10-5 mol but i get nothing close to that. could someone please explain if im doing something wrong n my equation and how i input it into a calculator. Thanks

[Sev]

Firstly, volume should be in Litres.  Secondly, concentration is 1.9*10^-3 not 1.9*10³.  Your calculator should have some kind of exponent key, if not, 1.9*10^-3 is just 1.9/1000.
 

[hightime]

okay thanks for the litres part i'm glad you caught that I can't believe I missed it.

so now i've arived at the 4.75 part but im wondering how they got 10-5 since im kind of confused still on it.

[Sev]

so now i've arived at the 4.75 part but im wondering how they got 10-5 since im kind of confused still on it.

Well, 0.025L*1.9*10^-3M = 4.75*10^-5 mol.

[Borek]

-5 is an exponent - do you know what scientific notation is? Look for button labelled EXP.