(a) Oxidation: Reaction in which a substance gains oxygen or addition of oxygen or removal of hydrogen in a reaction is called oxidation. Eg.: (i) 2Cu + O2 → 2CuO (ii) 4Al + 3O2 → 2Al2O3 (b) Reduction: Reaction in which a substance looses oxygen or removal of oxygen or gain of hydrogeRead more
(a) Oxidation: Reaction in which a substance gains oxygen or addition of oxygen or removal of hydrogen in a reaction is called oxidation.
Eg.:
(i) 2Cu + O2 → 2CuO
(ii) 4Al + 3O2 → 2Al2O3
(b) Reduction: Reaction in which a substance looses oxygen or removal of oxygen or gain of hydrogen in a reaction is called reduction.HEg.:
(i) CuO + H2 → Cu + H2O
oxygen is removed from copper oxide so reduction of CuO occurs.
(ii) H2S + Cl2 → 2HCl + S
gain of hydrogen by chlorine gas, so chlorine is reducted to form HCl.
The brown coloured element 'X' is copper. On heating in air it forms copper oxide which is black in colour. 2Cu(s) + O2(g) → 2CuO(s) Copper Oxygen Copper oxide (Brown (Black) color)
The brown coloured element ‘X’ is copper. On heating in air it forms copper oxide which is black in colour.
Iron articles is painted to prevent from rusting, so that iron article is do not come in contact with atmosphere oxygen and moisture. This will prevented it from rusting.
Iron articles is painted to prevent from rusting, so that iron article is do not come in contact with atmosphere oxygen and moisture. This will prevented it from rusting.
As nitrogen is inert gas it doesnot react with oil and fat. Nitrogen gas prevent oil and fat containing food items from rancidity. Food items get rancid means it smells and tastes bad due to oxidation with the atmosphere oxygen.
As nitrogen is inert gas it doesnot react with oil and fat. Nitrogen gas prevent oil and fat containing food items from rancidity. Food items get rancid means it smells and tastes bad due to oxidation with the atmosphere oxygen.
Corrosion: Metal are reacted with atmosphere oxygen, carbon dioxide and moisture and converted into metal oxides and carbonate. This phenomenon is called corrosion. Eg.: (i) Black coating on silver. 4Ag + 2H2S + O2 -----------> 2Ag2S + 2H2O (ii) Green coating on copper. Cu + CO2 + H2O -------Read more
Corrosion: Metal are reacted with atmosphere oxygen, carbon dioxide and moisture and converted into metal oxides and carbonate. This phenomenon is called corrosion.
Eg.:
(i) Black coating on silver.
4Ag + 2H2S + O2 ———–> 2Ag2S + 2H2O
(ii) Green coating on copper.
Cu + CO2 + H2O ———–> CuCO3. Cu (OH)2
(b) Rancidity: Oil and fat containing items when comes in contact with atmosphere oxygen they get oxidised and start smelling and tasting bad. The food item have gone rancid. This phenomeon is called rancidity.
Eg.:
(i) Smell and taste on food items get change after some times.
Explain the following in terms of gain or loss of oxygen with two examples each.
(a) Oxidation: Reaction in which a substance gains oxygen or addition of oxygen or removal of hydrogen in a reaction is called oxidation. Eg.: (i) 2Cu + O2 → 2CuO (ii) 4Al + 3O2 → 2Al2O3 (b) Reduction: Reaction in which a substance looses oxygen or removal of oxygen or gain of hydrogeRead more
(a) Oxidation: Reaction in which a substance gains oxygen or addition of oxygen or removal of hydrogen in a reaction is called oxidation.
Eg.:
(i) 2Cu + O2 → 2CuO
(ii) 4Al + 3O2 → 2Al2O3
(b) Reduction: Reaction in which a substance looses oxygen or removal of oxygen or gain of hydrogen in a reaction is called reduction.HEg.:
(i) CuO + H2 → Cu + H2O
oxygen is removed from copper oxide so reduction of CuO occurs.
(ii) H2S + Cl2 → 2HCl + S
See lessgain of hydrogen by chlorine gas, so chlorine is reducted to form HCl.
A shiny brown coloured element ‘X’ on heating in air becomes black in colour. Name the element ‘X’ and the black coloured compound formed.
The brown coloured element 'X' is copper. On heating in air it forms copper oxide which is black in colour. 2Cu(s) + O2(g) → 2CuO(s) Copper Oxygen Copper oxide (Brown (Black) color)
The brown coloured element ‘X’ is copper. On heating in air it forms copper oxide which is black in colour.
2Cu(s) + O2(g) → 2CuO(s)
See lessCopper Oxygen Copper oxide
(Brown (Black)
color)
Why do we apply paint on iron articles?
Iron articles is painted to prevent from rusting, so that iron article is do not come in contact with atmosphere oxygen and moisture. This will prevented it from rusting.
Iron articles is painted to prevent from rusting, so that iron article is do not come in contact with atmosphere oxygen and moisture. This will prevented it from rusting.
See lessOil and fat containing food items are flushed with nitrogen. Why?
As nitrogen is inert gas it doesnot react with oil and fat. Nitrogen gas prevent oil and fat containing food items from rancidity. Food items get rancid means it smells and tastes bad due to oxidation with the atmosphere oxygen.
As nitrogen is inert gas it doesnot react with oil and fat. Nitrogen gas prevent oil and fat containing food items from rancidity. Food items get rancid means it smells and tastes bad due to oxidation with the atmosphere oxygen.
See lessExplain the following terms with one example each.
Corrosion: Metal are reacted with atmosphere oxygen, carbon dioxide and moisture and converted into metal oxides and carbonate. This phenomenon is called corrosion. Eg.: (i) Black coating on silver. 4Ag + 2H2S + O2 -----------> 2Ag2S + 2H2O (ii) Green coating on copper. Cu + CO2 + H2O -------Read more
Corrosion: Metal are reacted with atmosphere oxygen, carbon dioxide and moisture and converted into metal oxides and carbonate. This phenomenon is called corrosion.
Eg.:
(i) Black coating on silver.
4Ag + 2H2S + O2 ———–> 2Ag2S + 2H2O
(ii) Green coating on copper.
Cu + CO2 + H2O ———–> CuCO3. Cu (OH)2
(b) Rancidity: Oil and fat containing items when comes in contact with atmosphere oxygen they get oxidised and start smelling and tasting bad. The food item have gone rancid. This phenomeon is called rancidity.
Eg.:
(i) Smell and taste on food items get change after some times.
See less