Assignment works
Subject : chemistry
Topic. : Draw on A4 size paper universal indicator and colour it. Write about corrosion of metals on A4 size sheets paper atleast 3 pages .
Answers
A universal indicator is a pH indicator made of a solution of several compounds that exhibits several smooth colour changes over a wide range pH values to indicate the acidity or alkalinity of solutions. Although there are several commercially available universal pH indicators, most are a variation of a formula patented by Yamada in 1933. Details of this patent can be found in Chemical Abstracts. Experiments with Yamada's universal indicator are also described in the Journal of Chemical Education.
A roll of universal indicator paper
Colors of universal indicator
A universal indicator is usually composed of water, Propanol, phenolphthalein sodium salt, sodium hydroxide, methyl red, bromothymol blue monosodium salt, and thymol blue monosodium salt.The colours that indicate the pH of a solution, after adding a universal indicator, are
pH range Description Colours Strong alkali Violet or Indigo
The colours from yellow to red indicate an acidic solutions
Corrosion is a natural process that converts a refined metal into a more chemically stable form such as oxide, hydroxide, carbonate or sulfide. It is the gradual destruction of materials (usually a metal) by chemical and/or electrochemical reaction with their environment. Corrosion engineering is the field dedicated to controlling and preventing corrosion.