### 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 = | ρ_{sample}ρ_{H20} | = ρ_{sample} at 4^{o}C |

### 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, V_{1,} with concentration, C_{1}, necessary to add to a volume of diluent, V _{2} - V_{1},to yeild desired concentration, C _{2} | V_{1} = | CC_{2}V_{2}_{1} |

### Reporting Analysis Results Based On Moisture

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

(19) Converting content (%Y) from OD to as received (AR) basis | %Y_{OD}= | %Y_{AR}x 100100 - %loss_{OD } |

(20) Converting content (%Y) from AR to OD basis | %Y_{AR}= | %Y_{OD} (100 - %loss_{OD} ) 100 |

(21) Converting content (%Y) from AR to arbitrary moisture (AM) basis | %Y = | %Y_{AR} (100 - %AM) (100 - %Moisture_{AR}) |

(22) Calculating weight of a sample on an AM basis | sample wt= | %dry matter_{AM}%dry matter_{AR} | x required wt |