The Separation of Barium, Lead, and Iron

Seth RatliffAndrew Cheatwood

Andrew Oliver

Abstract  An experiment in which a solution

containing ions of barium, lead, and iron needed to be precipitated out in to separate insoluble ions began February 27, 2011. In order to achieve this, sodium iodide (NaI), sodium sulfate (Na2SO4), and sodium sulfide (Na2S) were placed into the solution. When placing the sodium iodide (NaI) into the solution, lead was precipitated out. When placing sodium sulfate (Na2SO4) into the solution, Barium was precipitated out. When placing sodium sulfide (Na2S) into the solution Iron was precipitated out.

PurposeThe purpose of this lab is to separate the ions

of barium (Ba2+), lead (Pb2+), and tin (Sn2+).

Step 1 - Precipitation of Lead1. First, separate the Pb2+ from the solution by

putting 5 drops of sodium iodide (NaI) into the solution of Pb2+, Ba2+ , Sn2+. Do this until all the Pb2+ is separated from the solution creating insoluble plumbous iodide

2. In order to separate the insoluble plumbous iodide from the solution it will be placed in a centrifuge sending the insoluble plumbous iodide to the bottom of the solution allowing the remainder of the solution to be poured out.  

Precipitation of Lead

+ =

Precipitation of LeadObservationsSolution of Pb2+ , Ba2+ ,

Fe3+ ions Transparent yellow liquid Metallic smell

NaITransparent liquidNo odor

Solution + NaIcloudy yellow/orange

liquidSolution - Pb2+

Transparent orange liquid

Step 2 – Precipitation of Barium1. Separate Ba2+ from the solution by putting 5

drops of sodium sulfate (Na2SO4) into the solution of Ba2+, Sn2+. This should create insoluble barium sulfate. leaving only Sn2+.

2. In order to separate the insoluble barium sulfate from the solution it will be placed in a centrifuge sending the insoluble barium sulfate to the bottom of the solution allowing the remainder of the solution to be poured out.  

Precipitation of Barium ObservationsSolution of Ba2+ , Fe3+

ionsTransparent yellow liquid

Na₂SO₄Transparent liquid

Solution + Na₂SO₄Cloudy orange color

Solution - Ba2+

Transparent orange liquid

Note the barium at the bottom after being in centrifuge for 1-2 minutes

Step 3 – Precipitation of Iron1. Place 5 drops of sodium sulfide (NaS) into

the solution of Fe3+, which should create the insoluble compound Ferric Sulfide.

2. In order to separate the insoluble Ferric sulfide from the solution it will be placed in a centrifuge sending the insoluble Ferric sulfide to the bottom of the solution allowing the remainder of the solution to be poured out.  

Precipitation of IronObservationsSolution of Fe3+ ions

Transparent Yellow/orange liquid

Na ₂STransparent liquid

Solution + Na ₂SBlack

Solution - Fe3+ Transparent

Analysis of the precipitation of lead The solution containing the

ions of Pb2+ , Ba2+ , Fe3+ was a transparent yellow liquid. When placing the transparent liquid NaI into the solution to separate the lead ions; the solution became a cloudy yellow/orange color. After the Pb2+ was completely seperated from the solution; the solution returned to the transparent yellow liquid that it was.

Analysis of the precipitation of Barium The solution containing the

ions of Ba2+ , Fe3+ was a transparent yellow liquid. When placing the transparent liquid Na₂SO₄ into the solution to separate the Barium ions; the solution became a cloudy orange color. After the Ba2+ was completely separated from the solution; the solution returned to the transparent yellow liquid that it was.

Analysis of the precipitation of Iron The solution containing the

ions of Fe3+ was a transparent yellow liquid. When placing the transparent liquid Na2S into the solution to separate the Iron ions; the solution became black in color. After the Fe3+ was separated from the solution; the solution then became a clear/dark (see picture on right).

ConclusionThis lab was a success due to the fact that a solution

containing the ions of barium, lead, and iron were separated. The final results of the experiment confirm that all steps were completed correctly. Although the ions of the solution were separated, there may have been a few ions of each element left in the final liquid. This problem could have been avoided by keeping the solution in the centrifuge for a longer period of time for each step.