The man posing as a goldsmith likely used a solution of a strong acid, such as aqua regia, to clean the lady's gold bangles. Aqua regia is a mixture of concentrated nitric acid (HNO3) and concentrated hydrochloric acid (HCl) in a 1:3 ratio. 1. Aqua Regia Cleaning: When gold is exposed to aqua regia,Read more
The man posing as a goldsmith likely used a solution of a strong acid, such as aqua regia, to clean the lady’s gold bangles. Aqua regia is a mixture of concentrated nitric acid (HNO3) and concentrated hydrochloric acid (HCl) in a 1:3 ratio.
1. Aqua Regia Cleaning: When gold is exposed to aqua regia, the strong acids dissolve any impurities, tarnish, or other metals that may have adhered to the surface of the gold, making it appear shiny and new.
2. Dissolution of Impurities: The nitric acid in aqua regia can react with and dissolve impurities or other metals that are present in the gold bangles, leaving behind pure gold.
3. Weight Reduction: The reaction with the strong acids not only removes impurities but also removes a small amount of the gold itself in the form of soluble gold compounds, which are washed away with the solution. This is why the weight of the bangles would have reduced drastically.
The lady observed the bangles sparkling like new because the process effectively removed tarnish and impurities, leaving the pure gold with its characteristic shine. However, the loss of weight is due to the dissolution of some of the gold itself.
It’s important to note that using aqua regia to clean gold should be done with great caution, as it is a highly corrosive and hazardous solution. Only trained professionals should use it, and it’s typically used for refining gold and not for regular cleaning purposes. The man’s actions in this scenario were deceptive and unethical, as he used a dangerous chemical without the lady’s consent.
Copper is commonly used to make hot water tanks, while steel (an alloy of iron) is not typically used for this purpose. There are several reasons for this choice: 1. Corrosion Resistance: Copper is highly corrosion-resistant, especially in the presence of hot water. It forms a protective layer (coppRead more
Copper is commonly used to make hot water tanks, while steel (an alloy of iron) is not typically used for this purpose. There are several reasons for this choice:
1. Corrosion Resistance: Copper is highly corrosion-resistant, especially in the presence of hot water. It forms a protective layer (copper oxide) on its surface that further inhibits corrosion. In contrast, steel is prone to rust (iron oxide formation) when exposed to water and oxygen, which can compromise the tank’s integrity over time.
2. Heat Conductivity: Copper is an excellent conductor of heat. This means it heats up quickly and efficiently, which is desirable for heating water. It also retains heat well, keeping the water warm for longer periods. Steel, while a good conductor of heat, is not as efficient as copper.
3. Lightweight: Copper is relatively lightweight, making it easier to handle during tank manufacturing, installation, and maintenance. Steel, especially when used for large tanks, can be much heavier and cumbersome.
4. Aesthetic Appeal: Copper has a visually appealing reddish-brown color that many people find attractive. It is often used for exposed hot water tanks or tank exteriors, contributing to their aesthetics.
5. Longevity: Copper hot water tanks can have a long service life due to their corrosion resistance and durability. While steel tanks can be coated to reduce corrosion, copper tanks do not require such coatings.
6. Compatibility: Copper is compatible with different water qualities and does not react with water as aggressively as steel can when it comes to potential water quality issues.
7. Reduced Scaling: Copper is less prone to scaling, which is the buildup of mineral deposits in the tank, compared to steel. Scaling can reduce the efficiency of the hot water tank.
Despite these advantages, it’s worth noting that copper hot water tanks are typically more expensive than their steel counterparts. However, the longevity and efficiency of copper tanks often justify the initial investment for many consumers, especially in areas with aggressive water quality or where aesthetics are important.
A man went door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The bangles sparkled like new but their weight was reduced drastically. The lady was upset but after a futile argument the man beat a hasty retreat. Can you play the detective to find out the nature of the solution he had used?
The man posing as a goldsmith likely used a solution of a strong acid, such as aqua regia, to clean the lady's gold bangles. Aqua regia is a mixture of concentrated nitric acid (HNO3) and concentrated hydrochloric acid (HCl) in a 1:3 ratio. 1. Aqua Regia Cleaning: When gold is exposed to aqua regia,Read more
The man posing as a goldsmith likely used a solution of a strong acid, such as aqua regia, to clean the lady’s gold bangles. Aqua regia is a mixture of concentrated nitric acid (HNO3) and concentrated hydrochloric acid (HCl) in a 1:3 ratio.
1. Aqua Regia Cleaning: When gold is exposed to aqua regia, the strong acids dissolve any impurities, tarnish, or other metals that may have adhered to the surface of the gold, making it appear shiny and new.
2. Dissolution of Impurities: The nitric acid in aqua regia can react with and dissolve impurities or other metals that are present in the gold bangles, leaving behind pure gold.
3. Weight Reduction: The reaction with the strong acids not only removes impurities but also removes a small amount of the gold itself in the form of soluble gold compounds, which are washed away with the solution. This is why the weight of the bangles would have reduced drastically.
The lady observed the bangles sparkling like new because the process effectively removed tarnish and impurities, leaving the pure gold with its characteristic shine. However, the loss of weight is due to the dissolution of some of the gold itself.
It’s important to note that using aqua regia to clean gold should be done with great caution, as it is a highly corrosive and hazardous solution. Only trained professionals should use it, and it’s typically used for refining gold and not for regular cleaning purposes. The man’s actions in this scenario were deceptive and unethical, as he used a dangerous chemical without the lady’s consent.
See lessGive reasons why copper is used to make hot water tanks and not steel (an alloy of iron).
Copper is commonly used to make hot water tanks, while steel (an alloy of iron) is not typically used for this purpose. There are several reasons for this choice: 1. Corrosion Resistance: Copper is highly corrosion-resistant, especially in the presence of hot water. It forms a protective layer (coppRead more
Copper is commonly used to make hot water tanks, while steel (an alloy of iron) is not typically used for this purpose. There are several reasons for this choice:
1. Corrosion Resistance: Copper is highly corrosion-resistant, especially in the presence of hot water. It forms a protective layer (copper oxide) on its surface that further inhibits corrosion. In contrast, steel is prone to rust (iron oxide formation) when exposed to water and oxygen, which can compromise the tank’s integrity over time.
2. Heat Conductivity: Copper is an excellent conductor of heat. This means it heats up quickly and efficiently, which is desirable for heating water. It also retains heat well, keeping the water warm for longer periods. Steel, while a good conductor of heat, is not as efficient as copper.
3. Lightweight: Copper is relatively lightweight, making it easier to handle during tank manufacturing, installation, and maintenance. Steel, especially when used for large tanks, can be much heavier and cumbersome.
4. Aesthetic Appeal: Copper has a visually appealing reddish-brown color that many people find attractive. It is often used for exposed hot water tanks or tank exteriors, contributing to their aesthetics.
5. Longevity: Copper hot water tanks can have a long service life due to their corrosion resistance and durability. While steel tanks can be coated to reduce corrosion, copper tanks do not require such coatings.
6. Compatibility: Copper is compatible with different water qualities and does not react with water as aggressively as steel can when it comes to potential water quality issues.
7. Reduced Scaling: Copper is less prone to scaling, which is the buildup of mineral deposits in the tank, compared to steel. Scaling can reduce the efficiency of the hot water tank.
Despite these advantages, it’s worth noting that copper hot water tanks are typically more expensive than their steel counterparts. However, the longevity and efficiency of copper tanks often justify the initial investment for many consumers, especially in areas with aggressive water quality or where aesthetics are important.
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