Atom percentage excess

R45 represents the ratio of the signal intensities in the m/z 45 channel to the m/z 44 channel for the PDB CO2 standard and is defined as 0.0112372. The atom percentage excess (APE) C in the perhydro-/3C peak was obtained by subtracting the baseline atom percentage from Aat of all subsequent time points. Thus, APE represents the proportion of plasma /3C which is labeled at any point in time and takes into account natural abundance C or enrichment persisting from previous doses of pC]/3C in a given subject. 

Ethylene glycol has been used instead of water as solvent in the deposition of CdS films from cadmium acetate and sodium sulfide precursors. The films were amorphous and showed some excess cadmium (Cd/S atomic percentage ratio was 52.3/47.7) in EDX analysis.79... 

It is evident from the equation that the sodium is used in excess. Actually 61 5 g. of n-propyl bromide is 0 5 gram mol this will react with 0 5 gram atom or 11-5 g. of sodium, so that 100 per cent, excess was actually employed. The theoretical yield of n-hexane will be 0-25 gram mol or 21-5 g., since 2 mols of n-propyl bromide give 1 mol of n-hexane. The actual yield was 18 g., hence the percentage yield is (18/21-5) X 100 = 84 per cent. 

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