SL Chemistry IA

본 문서는 2018년 5월 아이비 시험을 위해 쓴 SL Chemistry IA입니다. 주제는 What is the relationship between different concentrations of NaCl (0.1M, 0.2M, 0.3M, 0.4M, 0.5M) and the DOC of water, determined by use of the Winkler method at 20°C?입니다. 만점에 가까운 점수를 받았습니다 (IB 7).

[본문내용]

Investigating the effect of differing concentrations of NaCl in water on the dissolved oxygen content (DOC) of water

Research question:​​ What is the relationship between different concentrations of NaCl (0.1M, 0.2M, 0.3M, 0.4M, 0.5M) and the DOC of water, determined by use of the Winkler method at 20​°​​C​?

Background Information: In this Internal Assessment, I am investigating the effects of different NaCl concentrations on the DOC of
water. I first encountered the topic of Biochemical Oxygen Demand in Topic 9: Redox of the SL Chemistry course through learning about the Winkler method – “​used to determine the concentration of dissolved oxygen in water samples.”​ (“Winkler Test”) I was personally interested in investigating the relationship between NaCl concentration and its effects on the
quality of water, interpreted through the DOC. Initially, research into procedures for DOC typically involved
BOD measurement, calculated through . However, BOD procedures typically require 5 OC OCD initial −D final
days of incubation, unsuitable to the time limits of my investigation. Moreover, BOD measurement
necessitates aerobic biological organisms to be in the water sample (“Biochemical Oxygen Demand”); this
conflicts my investigation’s purpose of solely perceiving the effect of changing NaCl concentration in distilled
water. Hence, I altered the standard BOD procedure learned in the Redox unit for the Winkler method to
investigate the relationship between NaCl concentration and DOC by shortening the preservation period to 8
hours and measuring only the final DOC instead of calculating the difference between initial and final DOC…

• 과목명: Chemistry
• 주제: What is the relationship between different concentrations of NaCl (0.1M, 0.2M, 0.3M, 0.4M, 0.5M) and the DOC of water, determined by use of the Winkler method at 20°C?
• 총 페이지수: 13 pages
• The file is in PDF format.