What I found challenging in the lesson combustion and flame?
Answer. It is more difficult to burn some combustible substances than others because different substances catch fire at different temperatures. Some substances have a low ignition temperature; therefore, they can catch fire more easily than others.
What is the theory of combustion?
Lavoisier’s theory that combustion was a reaction between the burning substance and the gas oxygen, present only to a limited extent in the atmosphere, was based on scientific principles, the most important of which was the law of the conservation of matter (after Einstein’s relativity theory, of matter and energy): …
When was combustion discovered?
The first approximation of the true nature of combustion was posited by French chemist Antoine-Laurent Lavoisier: he discovered in 1772 that the products of burned sulfur or phosphorus—in effect their ashes—outweighed the initial substances, and he postulated that the increased weight was due to their having combined …
What happens to a candle flame when it gets sufficient supply of air?
If the supply of air is sufficient, it can result in complete combustion. The reactants burn in oxygen and produce a limited number of products. When hydrocarbons burn in oxygen, the reaction primarily yields carbon dioxide and water.
Which part of the flame is used by Goldsmith and why?
A goldsmith uses the outer part of the candle flame for melting gold and silver. This is because, in this zone of flame, the temperature is the highest helping these metals to melt easily.
Which metal does not burn in fire?
In most cases, steel and iron in ordinary buildings will not burn during a fire, because the temperatures of the fire don’t get high enough for them to reach ignition temperature, but this doesn’t mean that given the right circumstances that they can’t burn.
How many types of combustion are there?
There are five different forms of combustion- complete combustion, incomplete combustion, rapid combustion, spontaneous combustion, and explosion.
Which is the hottest part of candle flame?
The innermost part of a candle flame is the hottest.
Which is hottest zone of a flame?
outer zone
Due to complete combustion, the outer zone is blue. This zone is the hottest in temperature when compared to the other zones. This blue coloured zone is the non-luminous part of the flame.
Which zone of flame does?
There are three zones in the candle flame in which the non – luminous zone is the zone of complete combustion, the luminous zone has limited oxygen supply and is moderately hot and the third zone is the dark zone which does not burn due to the absence of air.
Which flame has no combustion give reason?
Innermost zone is the zone of no combustion. It is also called as dark zone which is formed around the wick of the candle flame. Was this answer helpful?
Can glass catch fire?
Is it flammable? A fire will not ignite glass. However, glass can melt even if it doesn’t boil, though it won’t burn. The melting point is around 1400 degrees to 1600 degrees Celsius, or about 2,900 degrees Fahrenheit.
What causes combustion?
To summarize, for combustion to occur three things must be present: a fuel to be burned, a source of oxygen, and a source of heat.
What is the coldest part of a flame?
inner black zone
Why inner black zone of a candle is the coolest part of the flame.
What is the blue part of the flame called?
This is called the “combustion reaction zone” of the flame; it glows a delicate blue color. Sometimes, however, the fuel molecules don’t burn up right away. They clump together to form particles called soot, which then swirl around inside the body of the flame without actually burning.
What is combustion?
Combustion is a chemical process in which a substance reacts with oxygen to give off heat. Question 4. Define ignition temperature of a fuel. The lowest temperature at which a fuel catches fire is called its ignition temperature. Question 5. How does a matchstick catch fire?
How do you define spontaneous combustion?
Question 10. Define spontaneous combustion. A type of combustion in which the substance suddenly catches fire without the supply of heat or friction externally is called spontaneous combustion; e.g., forest fires. Question 11. Define explosion. Question 12. What is flame?
What is the result of incomplete combustion of fuels?
Answer: Incomplete combustion of fuels produces a very poisonous gas called carbon monoxide. Question 17: Name the fuel which is gradually replacing petrol and diesel in automobiles. Answer: The use of diesel and petrol as fuels in automobiles is being replaced by CNG (Compressed Natural Gas). Question 18: What is ignition temperature?
Why do some substances burn with a flame and others don’t?
Question 3: Why some substances burn with a flame while as some burn without a flame? Answer: The substances which vapourise during burning, give flames. For example, kerosene oil and molten wax rise through the wick and are vapourised during burning and form flames. Charcoal, on the other hand, does not vapourise and so does not produce a flame.