Admin Table of Contents
What are the precautions to be taken while diluting an acid?
Calculate the acid to be diluted for a certain volume of water. Cool the water to be used by keeping it in a container surrounded by ice. Add the cold distilled water to a large bottle. Add a small amount of acid. Let the solution cool. Add the remaining acid in small doses.
What should be taken when taking water samples?
Do not take samples near the bottom and do not skim the water surface in order to prevent the agitation of bottom sediments or surface floating debris. Also, collect samples upstream of the sampler and after any disturbed sediments have been cleared by the current.
What kind of water is needed for TOC analysis?
As mentioned, water with low TOC is necessary to run the analysis. High purity water with TOC < 5 ppb (µg/L) is delivered by water purification systems and available on-demand for TOC analysis. Figure 1: Example of performances of a water purification system over time.
How does storage of water affect TOC level?
Since it is known that storage of water leads to a degradation of its quality and an increase of TOC, and since contact with air contaminates high purity water, it was interesting to highlight and quantify these phenomena. TOC of commercially available analytical-grade bottled water was measured over time.
What should you do if you spill concentrated acids?
DO NOT TRY to place the soaked absorbent into the neoprene bottle, as fume evaporating from the concentrated acids pose a serious health hazard. If the spill runs underneath the fumehood; or lab equipment; or if it goes down sink call EH&S: 7-2273.
How to prepare a dilute solution of sulphuric acids?
Mix the solution by tilting the flask upside down. For the preparation of dilute solution of sulphuric and nitric acids, follow the same procedure. The acids should be used with utmost care. All the three acids are corrosive to skin. Add concentrated acids slowly to water with constant stirring.
What are the dangers of using concentrated acids?
Concentrated acids are very corrosive and dangerous chemicals that are commonly encountered in the laboratory. Some acids are also shock sensitive and when subjected to improper handling they can explode. Concentrated acids may be fatal if inhaled; and can cause severe eye and skin burns, severe respiratory and digestive tract burns.