"a cardiac catheterization is done in a healthy person. the blood sample withdrawn from the catheter shows 60% oxygen saturation, and the pressure recording shows oscillations from a maximum of 26 mm hg to a minimum of 14 mm hg. where was the catheter tip located? "

The answer should be vaporization 

Reaction involved in present system is :   c12h22o11 + h2o → 2 c6h12o6the reaction system is obeying following rate law:   rate = k[c12h22o11]thus, it is a first order reaction.now, for 1st order reactionrate constant (k) =  given: initial conc. = 3.0 g, final conc. = 2.7 g, t = 2.5 h∴rate constant (k) =  ∴ k = 0.04215 h-1now, for 1st order reaction, half life = 0.693/k = 0.693/0.04215 = 16.4 hthus correct answer is option b

Number of molecules=(12.01+2x15.9994)/112 x na