- Why is glass called the fourth state of matter? Write any two uses of water glass and lead crystal glass.
Glass is always in a liquid state, not solid or gaseous. It is also called a
super cooled liquid. So, it is called the fourth state of matter.Glass is
always in a liquid state, not solid or gaseous. It is also called a super
cooled liquid. So, it is called the fourth state of matter.
Any two used of water glass are:
- To make fire resistance accessories.
- To make gum or paste.
- It is used to make hard glass test tube.
- It is used to make lens, prism, etc.
- How can you prepare soap? Write with word/formula equation.
Soap can be prepared by treating vegetable or animal oils and fats with a
strong base such as sodium hydroxide or potassium hydroxide in an aqueous
fats/oil + alkali ⟶ soap + glycerol
C3H5(OOCR)3 ⟶ 3NaOOCR + C3H5(OH)3
where R = C17H35
- Write any two applications of thermosetting and thermoplastics. Mention any two characteristics of plastics.
Applications of thermosetting plastics are:
- To make handles of cooker.
- To make cup, plates, bowls, etc.
- To make polythene bags.
- To make pipes.
- Bad conductors of heat and electricity.
- It is light, do not corrode in air and water, can be recycled.
- How is ordinary glass made? Write any one use of ordinary glass.
Ordinary glass is made by fusing a mixture of 50% silica, 15% sodium
carbonate, 10% calcium carbonate and 25% glass pieces at 850°C in a
special type of tank furnace.
It is used for making bottles, light bulbs, window panes, etc.