GRAVIMETRIC ANALYSIS OF PHOSPHORUS IN PLANT FOOD

EXPERIMENT 5

Aim: To determine the amount of phosphorus in a commercial plant food

Objectives:

Apparatus & Chemicals:

Theoretical Background: ………………

Observations:

Mass of plant food (original sample) = 2 g

Weight of Filter Paper                                      =W₁= 0.87 g

Weight of Filter paper + Precipitate                =W₂= 2.85 g

Weight of Precipitate                                      =(W₂-W₁) g

Table 1: Measurement of Conductance.

Calculations:

2 g of soluble plant food yields (W₂-W₁) g ofMgNH₄PO₄.6H₂O

 [MgNH₄PO₄.6H₂O]        Ξ           P

     245 g                            Ξ          31 g

   (W₂-W₁) g ofMgNH₄PO₄.6H₂O Ξ    ‘X’      g of P

Amount of P = …………… g

Percent phosphorous in the original sample:

 Result & Analysis: …..

Experiment Oriented Task:

Analyze the various precautionary measure required to be taken during the precipitate formation, selection of washing liquids, filtration and drying process in the quantitative determination of phosphorous in the commercial plant food.

References: …