Question 15
Shyam was cooking potato curry on a chulha. To his surprise, he observed that the copper vessel was getting blackened from outside. It may be due to:
(a) proper combustion of fuel
(b) improper cooking of potato curry.
(c) improper combustion of the fuel.
(d) burning of copper vessel.
Shyam was cooking potato curry on a chulha. To his surprise, he observed that the copper vessel was getting blackened from outside. It may be due to:
(a) proper combustion of fuel
(b) improper cooking of potato curry.
(c) improper combustion of the fuel.
(d) burning of copper vessel.
The answer is (c).
The bottom of cooking vessels gets blackened due to incomplete combustion of fuel leading to wastage of fuel. This incomplete combustion happens due to the partial burning of fuel due to lack of oxygen.
When the fuel burns incompletely, a sooty flame appears which turns the bottom of the vessel black.
A reaction or process which entails only partial burning of a fuel. This may be due to a lack of oxygen or low temperature preventing the complete chemical reaction. CO is produced as a by product of incomplete combustion of carbon.
Incomplete combustion
Combustion refers to the process where a substance burns in the presence of Oxygen, giving off heat and light in the process. Commonly used fuels like natural gas and propane generally consist of carbon and hydrogen. When a fuel has a large ratio of hydrogen, more excess air must be provided. Water vapour is a by-product of burning hydrogen. To maintain its vaporous state, it robs heat from the flue gases, which would otherwise be available for more heat transfer.
The answer is (c).
The bottom of cooking vessels gets blackened due to incomplete combustion of fuel leading to wastage of fuel. This incomplete combustion happens due to the partial burning of fuel due to lack of oxygen.
When the fuel burns incompletely, a sooty flame appears which turns the bottom of the vessel black.
A reaction or process which entails only partial burning of a fuel. This may be due to a lack of oxygen or low temperature preventing the complete chemical reaction. CO is produced as a by product of incomplete combustion of carbon.
Incomplete combustion
Combustion refers to the process where a substance burns in the presence of Oxygen, giving off heat and light in the process. Commonly used fuels like natural gas and propane generally consist of carbon and hydrogen. When a fuel has a large ratio of hydrogen, more excess air must be provided. Water vapour is a by-product of burning hydrogen. To maintain its vaporous state, it robs heat from the flue gases, which would otherwise be available for more heat transfer.
