Experiment4 Chm 420

SUBJECT CODE EXPERIMENT TOPIC DATE

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CHM 420 4 Stoichiometry and Theoretical Yield

 NAME MATRIC NO I/C NO GROUP LECTURER NAME

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NABILAH BINTI AMINUDDIN AMINUDDIN 2014805292 950320145006 AS2301M1 DR. ZURAIDA KHUSAIMI

OBJECTIVE To identify the limiting reactant, excess reactant and to determinethe percent yield. THEORY

CHEMICALS AND APPARATUS Buret Erlenmeyer/conical flask Watch glass Oven Analytical balance Gravity Filter set : Filter paper funnel

0.5 M  1.5 M  

 

Or Suction Filtration Set :     

Unfolded filter paper Buchner funnel Adapter Vacuum filter flsk Rubber tube

METHODOLOGY 1. The volume of 0.5 M Ca   and 1.5 M   (as stated in Table 4.1 below) is dispensed from the buret on the side bench (prepared by laboratory assistant) into a clean conical flask. It would be nice to get as close as possible to the recommended volume.(All the volumes should be recorded to two decimal places). Table 4.1

Reaction

0.5 M Ca

1.5 M  

1 2

20ml 20ml

10ml 5ml

2. Initially a precipitate may not be observed. The flask is swirled and left aside for five minutes to allow precipitate to completely form. 3. The product is suction filter using a Buchner funnel (Figure 4.1) or the gravity fi lter the white solid. This is done by a piece of filter paper is folded into quarters and a funnel is made. This is placed inside the glass funnel. The solution poured into the centre of the filter paper taking care not to let it get above the level of the filter paper. 4. The sides of the conical is washed with a small amount of distilled water (use wash  bottle) and added this into filter paper. There is white solid inside the flask, however the time and effort involved in recouping this is not worth it ( One area of inefficiency). 5. The filter paper is carefully removed (it wil still be very moist) and placed it in n a  pre-weighed watch glass. The product is dried in the oven for a half an hour. 6. The product (Ca  is scrape from the filter paper onto the watch glass. Without tearing and scraping off some of the filter paper try to get as much as you can. The filter paper is discarded and the watch glass is returned to the oven for a fu rther ten minutes. The mass of the product is determined. The mass of product is reheated and redetermined the mass at least three times to complete dryness and/or until two weighings that are within 0.02g of one another. 7. The amount of Ca   obtained is compared with that expected. The limiting reactant, excess reactant is identified and the percent yield is calculated.

DATA/RESULT Reactions 1 Mass of the product,g (1st heat) Mass of the product,g (after reheating) Mass of the product,g (after reheating) Mass of the product,g

2