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## Grain Science and Industry

### Basic Laboratory Equations

 (1) Calculating number of moles in a given weight of a single substance mol = wtmol wt

 (2) Calculating weight of a substance given the number of moles wt = mol x mol wt

 (3) Calculating equivalent weight equiv wt = mole wt n

 (4) Calculating number of equivalents equiv = wtequiv wt = mol xn

 (5) Calculating Molarity of a given Volume of a single substance M = molVolume = mol x n

 (6) Calculating Normality of a given Volume of a single substance N = equiv V = wtmol wt x Volume = n x M

### Equations for Calculating Concentrations Based on Weight

 (7) Calculating the percent weight of a pure analyte in a given weight of solution %(w/w) = wt of analytewt of solution x 100

 (8) Calculating the percent weight of a pure analyte in a given volume of solution %(w/v) = wt of analytevolume of solution x 100

 (9) Calculating the weight of a pure analyte in a megagram sample ppm(w/w) = wt of analyte wt of solution x 10 6

 (10) Calculating the weight of a pure analyte in a megaliter sample ppm(w/v) = wt of analytevolume of solution x 10 6

 (11) Calculating the density of a substance ρ = wtvolume

 (12) Calculating the specific gravity of a substance sp gr = ρsampleρH20 = ρsample at 4oC

### Calculating the Weight or Volume of a Reagent to Prepare a Given Solution

 (13) Calculating the weight of a a substance needed to create a pre-assigned molar concentration wt = mol wt x M x V

 (14) Calculating (13), but correcting for the percentage of reagent purity wt = mol wt x M x V x 100%purity

 (15) Calculating (13), but given the percent weight of the analyte wt = %(w/v) x solution Volume 100

 (16) Calculating (13), but given the ppm of the analyte wt = ppm(w/v) x solution Volume 10-6

 (17) Calculating volume of reagent, V1, with concentration, C1, necessary to add to a volume of diluent, V2 - V1, to yeild desired concentration, C2 V1 = C2V2C1

### Reporting Analysis Results Based On Moisture

 (18) Calculating moisture loss due to being oven dried (OD) %lossOD = (wet wt - dry wt) x 100

 (19) Converting content (%Y) from OD to as received (AR) basis %YOD= %YARx 100100 - %lossOD

 (20) Converting content (%Y) from AR to OD basis %YAR= %YOD (100 - %lossOD ) 100

 (21) Converting content (%Y) from AR to arbitrary moisture (AM) basis %Y = %YAR (100 - %AM) (100 - %MoistureAR)

 (22) Calculating weight of a sample on an AM basis sample wt= %dry matterAM%dry matterAR x required wt