22 May Hydrogen Peroxide
7) Aqueous hydrogen peroxide is used to sterilise contact lenses. At room temperature, aqueous hydrogen peroxide decomposes very slowly to form water and oxygen. The decomposition can...
chemistry tuition question in Singapore Tag
22 May Vinegar – An Overview
a) (i) Give evidence from the diagram which demonstrates that the above reaction is exothermic. ……………………………………………………………………………………………… (ii) Construct the balanced chemical equation for the above reaction....
12 May Secondary Chemistry Tuition Question and Answer
Terephthoyl chloride and ethylene glycol react by polymerisation to produce a polymer called poly(ethylene terephthalate), commonly known as PET. PET is used to make soft...
12 May Organic Molecular Structures – Questions and Answers
Terephthoyl chloride and ethylene glycol react by polymerisation to produce a polymer called poly(ethylene terephthalate), commonly known as PET. PET is used to make soft...
12 May Basic questions of chemistry
Methane, CH4, is the major constituent of natural gas. (a) Draw a dot-and cross-diagram to show how the outer shell electrons are arranged in methane. (b) At a...
12 May Methane -The Main Constituent of Natural Gas
3 . Methane, CH4, is the major constituent of natural gas. (a) Draw a dot-and cross-diagram to show how the outer shell electrons are arranged in methane. ...
09 May Boron Nitride – An Overview
(a) Suggest why boron nitride with structure A can be used as a lubricant. ...
09 May Are you able to answer this Secondary Chemistry Tuition Question? (Part 2)
Several small pieces of magnesium are placed on a block of solid carbon dioxide. The solid carbon dioxide is at a temperature of -60 °C. The...
07 May Suggest Why Calcium Oxide Is Used To Neutralize Acidic Soils
9. Cement is made by heating clay with crushed calcium carbonate. During this process, the calcium carbonate is first converted to calcium oxide. (a) Suggest why calcium...
05 May Silicate – An Overview
2 . Sorrel is a small green plant.
(a) The pigments in the sorrel leaf can be separated by chromatography.
(i) Describe how chromatography can...