Two important uses of washing soda and baking soda are: 1) Washing soda: (a) Washing soda is used to remove permanent hardness of water. (b) It is used for domestic household washing purposes. (c) It is used in glass, soap, and paper industries. 2) Baking soda: (a) Baking powder is prepared by usingRead more
Two important uses of washing soda and baking soda are:
1) Washing soda:
(a) Washing soda is used to remove permanent hardness of water.
(b) It is used for domestic household washing purposes.
(c) It is used in glass, soap, and paper industries.
2) Baking soda:
(a) Baking powder is prepared by using baking soda. Baking powder is formed by the mixture of baking soda with a mild acid known as tartaric acid. When it is heated or mixed in water, CO2 gas is evolved that makes bread or cake fluffy.
(b) Soda-acid fire extinguishers are prepared by baking soda.
(c) It is used in making pakora more crispy.
A reaction in which an acid and base react with each other to form salt and water is known as neutralisation reaction. During this reaction energy is evolved in the form of heat. For example: (i) sodium hydroxide a strong base reacts with strong acid hydrochloric acid produces neutral salt sodium chRead more
A reaction in which an acid and base react with each other to form salt and water is known as neutralisation reaction. During this reaction energy is evolved in the form of heat.
For example:
(i) sodium hydroxide a strong base reacts with strong acid hydrochloric acid produces neutral salt sodium chloride and water molecules.
NaOH + HCl –> NaCl + H₂O
(ii) In case of indigestion which caused due to the excess production of hydrochloric acid in the stomach resulting in acidity, to neutralise the effect of acid an antacid, Mg(OH)₂ which is basic in nature is given, thus gives relief from indigestion.
Plaster of Paris (POP) is stored in a moisture-proof container because POP absorbs water vapour from the surrounding and reacts to form a hard mass solid known as gypsum. CaSO₄.1/2H₂O+ 3/2H₂O → CaSO₄.2H₂O
Plaster of Paris (POP) is stored in a moisture-proof container because POP absorbs water vapour from the surrounding and reacts to form a hard mass solid known as gypsum.
(a) Milkman shifts the pH of the fresh milk from 6 to slightly alkaline.This is because in an alkaline condition, milk does not coagulate into curd easily. (b) The milk is slightly more basic than usual milk, as base neutralise the acids produced to set the curd. Therefore, it takes a longer time toRead more
(a) Milkman shifts the pH of the fresh milk from 6 to slightly alkaline.This is because in an alkaline condition, milk does not coagulate into curd easily.
(b) The milk is slightly more basic than usual milk, as base neutralise the acids produced to set the curd. Therefore, it takes a longer time to convert the curd.
Fizzing will occur more strongly in test tube A than in test tube B. As test tube A contains hydrochloric acid (HCl) which is a strong acid that reacts vigorously with magnesium whereas acetic acid CH3COOH is weak acid. Being a strong acid, therefore hydrogen gas evolved a faster speed that's why iRead more
Fizzing will occur more strongly in test tube A than in test tube B. As test tube A contains hydrochloric acid (HCl) which is a strong acid that reacts vigorously with magnesium whereas acetic acid CH3COOH is weak acid. Being a strong acid, therefore hydrogen gas evolved a faster speed that’s why it’s more fizzing occurs.
(a) Solution D is neutral having pH 7 (b) Solution C is strong alkaline with pH 11 (c) Solution B is strong acidic with pH 1 (d) Solution A is weak acidic with pH 4 (e) Solution E is weak alkaline with pH 9 11 < 9 < 7 < 4 < 1. The pH can be arranged in the increasing order of the concentRead more
(a) Solution D is neutral having pH 7
(b) Solution C is strong alkaline with pH 11
(c) Solution B is strong acidic with pH 1
(d) Solution A is weak acidic with pH 4
(e) Solution E is weak alkaline with pH 9
11 < 9 < 7 < 4 < 1. The pH can be arranged in the increasing order of the concentration of hydrogen ions.
The acidic behaviour of acid is due to the presence of hydrogen ions. The acids will not show its acidic behaviour in the absence of water, this is because acids do not dissociate to produce H+(aq) ions in the absence of water.
The acidic behaviour of acid is due to the presence of hydrogen ions. The acids will not show its acidic behaviour in the absence of water, this is because acids do not dissociate to produce H+(aq) ions in the absence of water.
Distilled water is a pure form of water that does not contain any ionic species. Therefore, it does not conduct electricity. Rain water, being an impure form of water, contains many ionic species such as acids and therefore it conducts electricity.
Distilled water is a pure form of water that does not contain any ionic species. Therefore, it does not conduct electricity. Rain water, being an impure form of water, contains many ionic species such as acids and therefore it conducts electricity.
Because glucose and alcohol do not dissociate into ions. Therefore these solution are not considered as acid - Experimental verification : Procedure : Two nails are fitted in a cork and they are kept in a 100 ml beaker. Then the nails are connected to the two terminals of the battery of 6 volt alongRead more
Because glucose and alcohol do not dissociate into ions. Therefore these solution are not considered as acid –
Experimental verification :
Procedure : Two nails are fitted in a cork and they are kept in a 100 ml beaker. Then the nails are connected to the two terminals of the battery of 6 volt along with a bulb and a switch. Now some dilute HCl is added in the beaker and allows the current to pass through the circuit. The same experiment is carried out with glucose and alcohol solutions separately in place of HCl.
Observations :
The bulb glows only in HCl solution only. Because HCl solution dissociates into H+ and Cl– ions which conduct electricity whereas glucose and alcohol solutions do not dissociate into ions and so, these solutions do not conduct electricity. So the bulb doesn’t glow.
Interpretation :
Activity above hereby proved that all acids contain hydrogen but not all compounds that contain hydrogen are acids. Therefore compounds such as alcohols and glucose contain hydrogen, and are not categorised as acids.
Give two important uses of washing soda and baking soda
Two important uses of washing soda and baking soda are: 1) Washing soda: (a) Washing soda is used to remove permanent hardness of water. (b) It is used for domestic household washing purposes. (c) It is used in glass, soap, and paper industries. 2) Baking soda: (a) Baking powder is prepared by usingRead more
Two important uses of washing soda and baking soda are:
1) Washing soda:
(a) Washing soda is used to remove permanent hardness of water.
(b) It is used for domestic household washing purposes.
(c) It is used in glass, soap, and paper industries.
2) Baking soda:
(a) Baking powder is prepared by using baking soda. Baking powder is formed by the mixture of baking soda with a mild acid known as tartaric acid. When it is heated or mixed in water, CO2 gas is evolved that makes bread or cake fluffy.
(b) Soda-acid fire extinguishers are prepared by baking soda.
See less(c) It is used in making pakora more crispy.
What is a neutralisation reaction? Give two examples.
A reaction in which an acid and base react with each other to form salt and water is known as neutralisation reaction. During this reaction energy is evolved in the form of heat. For example: (i) sodium hydroxide a strong base reacts with strong acid hydrochloric acid produces neutral salt sodium chRead more
A reaction in which an acid and base react with each other to form salt and water is known as neutralisation reaction. During this reaction energy is evolved in the form of heat.
For example:
(i) sodium hydroxide a strong base reacts with strong acid hydrochloric acid produces neutral salt sodium chloride and water molecules.
NaOH + HCl –> NaCl + H₂O
(ii) In case of indigestion which caused due to the excess production of hydrochloric acid in the stomach resulting in acidity, to neutralise the effect of acid an antacid, Mg(OH)₂ which is basic in nature is given, thus gives relief from indigestion.
Mg(OH)₂ + 2HCl –> MgCl₂ + 2H₂O
See lessPlaster of Paris should be stored in a moisture-proof container. Explain why?
Plaster of Paris (POP) is stored in a moisture-proof container because POP absorbs water vapour from the surrounding and reacts to form a hard mass solid known as gypsum. CaSO₄.1/2H₂O+ 3/2H₂O → CaSO₄.2H₂O
Plaster of Paris (POP) is stored in a moisture-proof container because POP absorbs water vapour from the surrounding and reacts to form a hard mass solid known as gypsum.
CaSO₄.1/2H₂O+ 3/2H₂O → CaSO₄.2H₂O
See lessA milkman adds a very small amount of baking soda to fresh milk.
(a) Milkman shifts the pH of the fresh milk from 6 to slightly alkaline.This is because in an alkaline condition, milk does not coagulate into curd easily. (b) The milk is slightly more basic than usual milk, as base neutralise the acids produced to set the curd. Therefore, it takes a longer time toRead more
(a) Milkman shifts the pH of the fresh milk from 6 to slightly alkaline.This is because in an alkaline condition, milk does not coagulate into curd easily.
(b) The milk is slightly more basic than usual milk, as base neutralise the acids produced to set the curd. Therefore, it takes a longer time to convert the curd.
See lessFresh milk has a pH of 6. How do you think the pH will change as it turns into curd? Explain your answer.
Normally the pH of milk is 6, as curd is acidic in nature pH will reduce.
Normally the pH of milk is 6, as curd is acidic in nature pH will reduce.
See lessEqual lengths of magnesium ribbons are taken in test tubes A and B. Hydrochloric acid (HCl) is added to test tube A, while acetic acid (CH3COOH) is added to test tube B. Amount and concentration taken for both the acids are same. In which test tube will the fizzing occur more vigorously and why?
Fizzing will occur more strongly in test tube A than in test tube B. As test tube A contains hydrochloric acid (HCl) which is a strong acid that reacts vigorously with magnesium whereas acetic acid CH3COOH is weak acid. Being a strong acid, therefore hydrogen gas evolved a faster speed that's why iRead more
Fizzing will occur more strongly in test tube A than in test tube B. As test tube A contains hydrochloric acid (HCl) which is a strong acid that reacts vigorously with magnesium whereas acetic acid CH3COOH is weak acid. Being a strong acid, therefore hydrogen gas evolved a faster speed that’s why it’s more fizzing occurs.
See lessFive solutions A,B,C,D and E when tested with universal indicator showed pH as 4,1,11,7 and 9, respectively. Which solution is
(a) Solution D is neutral having pH 7 (b) Solution C is strong alkaline with pH 11 (c) Solution B is strong acidic with pH 1 (d) Solution A is weak acidic with pH 4 (e) Solution E is weak alkaline with pH 9 11 < 9 < 7 < 4 < 1. The pH can be arranged in the increasing order of the concentRead more
(a) Solution D is neutral having pH 7
(b) Solution C is strong alkaline with pH 11
(c) Solution B is strong acidic with pH 1
(d) Solution A is weak acidic with pH 4
(e) Solution E is weak alkaline with pH 9
11 < 9 < 7 < 4 < 1. The pH can be arranged in the increasing order of the concentration of hydrogen ions.
See lessWhy do acids not show acidic behaviour in the absence of water?
The acidic behaviour of acid is due to the presence of hydrogen ions. The acids will not show its acidic behaviour in the absence of water, this is because acids do not dissociate to produce H+(aq) ions in the absence of water.
The acidic behaviour of acid is due to the presence of hydrogen ions. The acids will not show its acidic behaviour in the absence of water, this is because acids do not dissociate to produce H+(aq) ions in the absence of water.
See lessWhy does distilled water not conduct electricity, whereas rain water does?
Distilled water is a pure form of water that does not contain any ionic species. Therefore, it does not conduct electricity. Rain water, being an impure form of water, contains many ionic species such as acids and therefore it conducts electricity.
Distilled water is a pure form of water that does not contain any ionic species. Therefore, it does not conduct electricity. Rain water, being an impure form of water, contains many ionic species such as acids and therefore it conducts electricity.
See lessCompounds such as alcohols and glucose also contain hydrogen but are not categorised as acids. Describe an Activity to prove it.
Because glucose and alcohol do not dissociate into ions. Therefore these solution are not considered as acid - Experimental verification : Procedure : Two nails are fitted in a cork and they are kept in a 100 ml beaker. Then the nails are connected to the two terminals of the battery of 6 volt alongRead more
Because glucose and alcohol do not dissociate into ions. Therefore these solution are not considered as acid –
Experimental verification :
Procedure : Two nails are fitted in a cork and they are kept in a 100 ml beaker. Then the nails are connected to the two terminals of the battery of 6 volt along with a bulb and a switch. Now some dilute HCl is added in the beaker and allows the current to pass through the circuit. The same experiment is carried out with glucose and alcohol solutions separately in place of HCl.
Observations :
The bulb glows only in HCl solution only. Because HCl solution dissociates into H+ and Cl– ions which conduct electricity whereas glucose and alcohol solutions do not dissociate into ions and so, these solutions do not conduct electricity. So the bulb doesn’t glow.
Interpretation :
Activity above hereby proved that all acids contain hydrogen but not all compounds that contain hydrogen are acids. Therefore compounds such as alcohols and glucose contain hydrogen, and are not categorised as acids.
See less