(i) Sodium (Na) is oxidised as it gains oxygen and oxygen gets reduced. (ii) Copper oxide (CuO) is reduced to copper (Cu) while hydrogen (H₂) gets oxidised to water (H₂O). For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/class-10/science/chapter-1/
(i) Sodium (Na) is oxidised as it gains oxygen and oxygen gets reduced.
(ii) Copper oxide (CuO) is reduced to copper (Cu) while hydrogen (H₂) gets oxidised to water (H₂O).
Sodium carbonate reacts with calcium chloride to form calcium carbonate and sodium chloride. 𝑁𝑎₂𝐶𝑂₃+𝐶𝑎𝐶𝑙₂→ 𝐶𝑎𝐶𝑂₃ +2𝑁𝑎𝐶𝑙 In this reaction, sodium carbonate and calcium chloride exchange ions to form two new compounds. Hence, it is a double displacement reaction.
Sodium carbonate reacts with calcium chloride to form calcium carbonate and sodium chloride.
𝑁𝑎₂𝐶𝑂₃+𝐶𝑎𝐶𝑙₂→ 𝐶𝑎𝐶𝑂₃ +2𝑁𝑎𝐶𝑙
In this reaction, sodium carbonate and calcium chloride exchange ions to form two new compounds. Hence, it is a double displacement reaction.
When an iron nail is dipped in a copper sulphate solution, iron (which is more reactive than copper) displaces copper from copper sulphate solution forming iron sulphate, which is green in colour. 𝐶𝑢𝑆𝑂₄+𝐹𝑒 → 𝐹𝑒𝑆𝑂₄+𝐶𝑢 Therefore, the blue colour of copper sulphate solution fades and green colour appeaRead more
When an iron nail is dipped in a copper sulphate solution, iron (which is more reactive than copper) displaces copper from copper sulphate solution forming iron sulphate, which is green in colour.
𝐶𝑢𝑆𝑂₄+𝐹𝑒 → 𝐹𝑒𝑆𝑂₄+𝐶𝑢
Therefore, the blue colour of copper sulphate solution fades and green colour appears.
During the Electrolysis of water, hydrogen and oxygen is get separated by the electricity. Water (H2O) contains two parts hydrogen and one part oxygen. Since hydrogen goes to one test tube and oxygen goes to another, the amount of gas collected in one of the test tubes is double of the amount collecRead more
During the Electrolysis of water, hydrogen and oxygen is get separated by the electricity. Water (H2O) contains two parts hydrogen and one part oxygen. Since hydrogen goes to one test tube and oxygen goes to another, the amount of gas collected in one of the test tubes is double of the amount collected in the other.
(i) The substance ‘X’ is calcium oxide. Its chemical formula is CaO. (ii) Calcium oxide reacts vigorously with water to form calcium hydroxide (slaked lime) 𝐶𝑎𝑂+𝐻₂𝑂 → 𝐶𝑎(𝑂𝐻)₂
(i) The substance ‘X’ is calcium oxide. Its chemical formula is CaO.
(ii) Calcium oxide reacts vigorously with water to form calcium hydroxide (slaked lime)
𝐶𝑎𝑂+𝐻₂𝑂 → 𝐶𝑎(𝑂𝐻)₂
(i) BaCl₂(aq)+Na2SO₄(aq) → BaSO₄(s) +2NaCl(aq) (ii) NaOH(aq) + HCl(aq) → NaCl(aq)+H₂O(l) For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/class-10/science/chapter-1/
Magnesium is very reactive metal like (Na, Ca, etc.). When it expose to air it reacts with oxygen to form a layer magnesium oxide (MgO) on its surface. 𝑀𝑔⏟𝑀𝑎𝑔𝑛𝑒𝑠𝑖𝑢𝑚+𝑂₂⏟𝑂𝑥𝑖𝑔𝑒𝑛 → 2𝑀𝑔𝑂⏟ 𝑀𝑎𝑔𝑛𝑒𝑠𝑖𝑢𝑚 𝑂𝑥𝑖𝑑𝑒 This layer of magnesium oxide is quite stable and prevents further reaction of magnesium with oxygen.Read more
Magnesium is very reactive metal like (Na, Ca, etc.). When it expose to air it reacts with oxygen to form a layer magnesium oxide (MgO) on its surface.
𝑀𝑔⏟𝑀𝑎𝑔𝑛𝑒𝑠𝑖𝑢𝑚+𝑂₂⏟𝑂𝑥𝑖𝑔𝑒𝑛 → 2𝑀𝑔𝑂⏟ 𝑀𝑎𝑔𝑛𝑒𝑠𝑖𝑢𝑚 𝑂𝑥𝑖𝑑𝑒
This layer of magnesium oxide is quite stable and prevents further reaction of magnesium with oxygen. The magnesium ribbon is cleaned by sand paper to remove this layer so that the underlying metal can be used for the reaction.
(a) Corrosion: Corrosion is defined as a process where materials, usually metals, deteriorate as a result of a chemical reaction with air, moisture, chemicals, etc. • Iron, in the presence of moisture, reacts with oxygen to form hydrated iron oxide (a brown flaky substance) called rust. • Silver artRead more
(a) Corrosion: Corrosion is defined as a process where materials, usually metals, deteriorate as a result of a chemical reaction with air, moisture, chemicals, etc.
• Iron, in the presence of moisture, reacts with oxygen to form hydrated iron oxide (a brown flaky substance) called rust.
• Silver articles become black after some time when exposed to air. This is because it reacts with sulphur in the air to form a coating of silver sulphide.
• Copper reacts with moist carbon dioxide in the air and slowly loses its shiny brown surface and gains a green coat. This green substance is copper carbonate.
(b) Rancidity: The process of oxidation of fats and oils that can be easily noticed by the change in taste and smell is known as rancidity.
For example, the taste and smell of butter changes when kept for long. Rancidity can be avoided by:
• Storing food in air tight containers
• Adding antioxidants
• Storing food in an environment of nitrogen
Nitrogen is an inert gas (at room temperature) and does not easily react with oil and fat containing items. On the other hand, oxygen reacts with food substances and makes them rancid. Thus, bags used in packing food items are flushed with nitrogen gas to remove oxygen inside the pack. When oxygen iRead more
Nitrogen is an inert gas (at room temperature) and does not easily react with oil and fat containing items. On the other hand, oxygen reacts with food substances and makes them rancid. Thus, bags used in packing food items are flushed with nitrogen gas to remove oxygen inside the pack. When oxygen is not present inside the pack, rancidity of oil and fat containing food items is avoided.
Identify the substances that are oxidised and the substances that are reduced in the following reactions.
(i) Sodium (Na) is oxidised as it gains oxygen and oxygen gets reduced. (ii) Copper oxide (CuO) is reduced to copper (Cu) while hydrogen (H₂) gets oxidised to water (H₂O). For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/class-10/science/chapter-1/
(i) Sodium (Na) is oxidised as it gains oxygen and oxygen gets reduced.
(ii) Copper oxide (CuO) is reduced to copper (Cu) while hydrogen (H₂) gets oxidised to water (H₂O).
For more answers visit to website:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-10/science/chapter-1/
Give an example of a double displacement reaction other than the one given in Activity 1.10.
Sodium carbonate reacts with calcium chloride to form calcium carbonate and sodium chloride. 𝑁𝑎₂𝐶𝑂₃+𝐶𝑎𝐶𝑙₂→ 𝐶𝑎𝐶𝑂₃ +2𝑁𝑎𝐶𝑙 In this reaction, sodium carbonate and calcium chloride exchange ions to form two new compounds. Hence, it is a double displacement reaction.
Sodium carbonate reacts with calcium chloride to form calcium carbonate and sodium chloride.
See less𝑁𝑎₂𝐶𝑂₃+𝐶𝑎𝐶𝑙₂→ 𝐶𝑎𝐶𝑂₃ +2𝑁𝑎𝐶𝑙
In this reaction, sodium carbonate and calcium chloride exchange ions to form two new compounds. Hence, it is a double displacement reaction.
Why does the colour of copper sulphate solution change when an iron nail is dipped in it?
When an iron nail is dipped in a copper sulphate solution, iron (which is more reactive than copper) displaces copper from copper sulphate solution forming iron sulphate, which is green in colour. 𝐶𝑢𝑆𝑂₄+𝐹𝑒 → 𝐹𝑒𝑆𝑂₄+𝐶𝑢 Therefore, the blue colour of copper sulphate solution fades and green colour appeaRead more
When an iron nail is dipped in a copper sulphate solution, iron (which is more reactive than copper) displaces copper from copper sulphate solution forming iron sulphate, which is green in colour.
𝐶𝑢𝑆𝑂₄+𝐹𝑒 → 𝐹𝑒𝑆𝑂₄+𝐶𝑢
Therefore, the blue colour of copper sulphate solution fades and green colour appears.
For more answers visit to website:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-10/science/chapter-1/
Why is the amount of gas collected in one of the test tubes in Activity 1.7 double of the amount collected in the other? Name this gas.
During the Electrolysis of water, hydrogen and oxygen is get separated by the electricity. Water (H2O) contains two parts hydrogen and one part oxygen. Since hydrogen goes to one test tube and oxygen goes to another, the amount of gas collected in one of the test tubes is double of the amount collecRead more
During the Electrolysis of water, hydrogen and oxygen is get separated by the electricity. Water (H2O) contains two parts hydrogen and one part oxygen. Since hydrogen goes to one test tube and oxygen goes to another, the amount of gas collected in one of the test tubes is double of the amount collected in the other.
For more answers visit to website:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-10/science/chapter-1/
A solution of a substance ‘X’ is used for whitewashing.
(i) The substance ‘X’ is calcium oxide. Its chemical formula is CaO. (ii) Calcium oxide reacts vigorously with water to form calcium hydroxide (slaked lime) 𝐶𝑎𝑂+𝐻₂𝑂 → 𝐶𝑎(𝑂𝐻)₂
(i) The substance ‘X’ is calcium oxide. Its chemical formula is CaO.
See less(ii) Calcium oxide reacts vigorously with water to form calcium hydroxide (slaked lime)
𝐶𝑎𝑂+𝐻₂𝑂 → 𝐶𝑎(𝑂𝐻)₂
Write a balanced chemical equation with state symbols for the following reactions.
(i) BaCl₂(aq)+Na2SO₄(aq) → BaSO₄(s) +2NaCl(aq) (ii) NaOH(aq) + HCl(aq) → NaCl(aq)+H₂O(l) For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/class-10/science/chapter-1/
(i) BaCl₂(aq)+Na2SO₄(aq) → BaSO₄(s) +2NaCl(aq)
(ii) NaOH(aq) + HCl(aq) → NaCl(aq)+H₂O(l)
For more answers visit to website:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-10/science/chapter-1/
Write the balanced equation for the following chemical reactions.
(i) 𝐻₂ + 𝐶𝑙₂ → 2𝐻𝐶𝑙 (ii) 3𝐵𝑎𝐶𝑙₂ +𝐴𝑙₂(𝑆𝑂₄) ₃ → 3𝐵𝑎𝑆𝑂₄ +2𝐴𝑙𝐶𝑙3 (iii) 2𝑁𝑎 +2𝐻₂𝑂→ 2𝑁𝑎𝑂𝐻+𝐻₂ For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/class-10/science/chapter-1/
(i) 𝐻₂ + 𝐶𝑙₂ → 2𝐻𝐶𝑙
(ii) 3𝐵𝑎𝐶𝑙₂ +𝐴𝑙₂(𝑆𝑂₄) ₃ → 3𝐵𝑎𝑆𝑂₄ +2𝐴𝑙𝐶𝑙3
(iii) 2𝑁𝑎 +2𝐻₂𝑂→ 2𝑁𝑎𝑂𝐻+𝐻₂
For more answers visit to website:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-10/science/chapter-1/
Why Should a magnesium ribbon be cleaned before burning in air?
Magnesium is very reactive metal like (Na, Ca, etc.). When it expose to air it reacts with oxygen to form a layer magnesium oxide (MgO) on its surface. 𝑀𝑔⏟𝑀𝑎𝑔𝑛𝑒𝑠𝑖𝑢𝑚+𝑂₂⏟𝑂𝑥𝑖𝑔𝑒𝑛 → 2𝑀𝑔𝑂⏟ 𝑀𝑎𝑔𝑛𝑒𝑠𝑖𝑢𝑚 𝑂𝑥𝑖𝑑𝑒 This layer of magnesium oxide is quite stable and prevents further reaction of magnesium with oxygen.Read more
Magnesium is very reactive metal like (Na, Ca, etc.). When it expose to air it reacts with oxygen to form a layer magnesium oxide (MgO) on its surface.
See less𝑀𝑔⏟𝑀𝑎𝑔𝑛𝑒𝑠𝑖𝑢𝑚+𝑂₂⏟𝑂𝑥𝑖𝑔𝑒𝑛 → 2𝑀𝑔𝑂⏟ 𝑀𝑎𝑔𝑛𝑒𝑠𝑖𝑢𝑚 𝑂𝑥𝑖𝑑𝑒
This layer of magnesium oxide is quite stable and prevents further reaction of magnesium with oxygen. The magnesium ribbon is cleaned by sand paper to remove this layer so that the underlying metal can be used for the reaction.
Explain the following terms with one example each.
(a) Corrosion: Corrosion is defined as a process where materials, usually metals, deteriorate as a result of a chemical reaction with air, moisture, chemicals, etc. • Iron, in the presence of moisture, reacts with oxygen to form hydrated iron oxide (a brown flaky substance) called rust. • Silver artRead more
(a) Corrosion: Corrosion is defined as a process where materials, usually metals, deteriorate as a result of a chemical reaction with air, moisture, chemicals, etc.
• Iron, in the presence of moisture, reacts with oxygen to form hydrated iron oxide (a brown flaky substance) called rust.
• Silver articles become black after some time when exposed to air. This is because it reacts with sulphur in the air to form a coating of silver sulphide.
• Copper reacts with moist carbon dioxide in the air and slowly loses its shiny brown surface and gains a green coat. This green substance is copper carbonate.
(b) Rancidity: The process of oxidation of fats and oils that can be easily noticed by the change in taste and smell is known as rancidity.
For example, the taste and smell of butter changes when kept for long. Rancidity can be avoided by:
• Storing food in air tight containers
• Adding antioxidants
• Storing food in an environment of nitrogen
For more answers visit to website:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-10/science/chapter-1/
Oil and fat containing food items are flushed with nitrogen. Why?
Nitrogen is an inert gas (at room temperature) and does not easily react with oil and fat containing items. On the other hand, oxygen reacts with food substances and makes them rancid. Thus, bags used in packing food items are flushed with nitrogen gas to remove oxygen inside the pack. When oxygen iRead more
Nitrogen is an inert gas (at room temperature) and does not easily react with oil and fat containing items. On the other hand, oxygen reacts with food substances and makes them rancid. Thus, bags used in packing food items are flushed with nitrogen gas to remove oxygen inside the pack. When oxygen is not present inside the pack, rancidity of oil and fat containing food items is avoided.
For more answers visit to website:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-10/science/chapter-1/