GRAVIMETRIC ANALYSIS

Gravimetric Analysis

quantitative analysis by weight

Gravimetric Analysis

is based on direct measurement

of weight or mass of a compound formed from a chemical reaction.

Precipitation

Decomposition by ignition

Volatilization

How do we obtain product?

Gravimetric Analysis (Advantages)

is the oldest, most fundamental, most versatile and

most unpopular method of quantitative analysis and it gives accurate

determination (if done correctly)

Gravimetric Analysis (Disadvantages)

Tedious, long process/time-consuming

%Purity Calculations

(applicable for precipitation method)

%Purity Calculations

Percent = W x GF/S x 100

Gooch Filtration Crucible

Fritted-Glass Crucibles

Types of Crucible

500 to 550 degree C

Very Dull-Red

550 to 700 degree C

Dull-Red

800 to 1000 degree C

Bright Red

1000 to 1200 degree C

Yellow-Red

1200 to 1600 degree C

White

residue

The weight of the _ represents the quantity of ZnO in the weight

of the Paste taken for the assay.

ZnO

The weight of the residue represents the quantity of _ in the weight

of the Paste taken for the assay.

Paste

The weight of the residue represents the quantity of ZnO in the weight

of the _ taken for the assay.

Zinc Oxide and Salicylic Acid Paste

_ contains not less than 23.5 – 25.5% of zinc oxide (ZnO)