Chapter-5 Acids, Bases, and Salts

Explanation:

Acids are chemical compounds that can donate protons or accept electrons in a chemical reaction. They are sour. Acids react with bases to form salts with a pH value of less than 7. Common acids available in market products include hydrochloric acid, sulfuric acid, acetic acid, and citric acid.

Explanation:

Salts are chemical compounds formed by the reaction of an acid with a base. They consist of positively and negatively charged ions held together by ionic bonds. Some commonly available salts include regular table salt (sodium chloride), Epsom salt (magnesium sulfate), and baking soda (sodium bicarbonate). Table salt is used regularly to enhance the taste of our food. 

Explanation:

Antacids are used to treat acidity because they neutralize excess stomach acid. Antacid consists of calcium carbonate, magnesium hydroxide, and aluminum hydroxide, which react with the acid in the stomach to form salt and water, reducing the stomach contents' acidity. This can help to relieve symptoms of heartburn and indigestion. 

Explanation:

Antacids in the market can be found as liquid and chewable tablets. Two commonly used antacids are: 

Tums: Tums is an antacid containing calcium carbonate as its active ingredient. It works by neutralizing stomach acid, relieving symptoms of heartburn, indigestion, and upset stomach. 

Maalox: Maalox is an antacid containing a combination of aluminum hydroxide and magnesium hydroxide. It works by neutralizing stomach acid and reducing the amount of acid the stomach lining produces.

Explanation:

Indigestion can be caused by a variety of factors, including overeating, consuming spicy or fatty foods, drinking alcohol or caffeine, smoking, stress, and certain medications. Indigestion can also be caused due to some underlying medical conditions, such as ulcers.

Explanation:

Acid rain is a type of precipitation characterized by high acidity levels. It occurs when sulfur dioxide and nitrogen oxides are released into the atmosphere from burning fossil fuels and other industrial activities. These chemicals react with water, oxygen, and other substances to form sulfuric and nitric acids, which can fall to the ground as rain, snow, sleet, or fog.

Explanation:

Litmus paper determines whether a substance is acidic or basic. It works by changing color in response to the acidity or basicity of the solution it is in contact with. The natural color of litmus paper is light blue. When exposed to an acidic solution, it turns red; when exposed to a basic solution, it turns blue.

Explanation:

When a drop of dilute sulphuric acid is added to China rose indicator, the indicator will turn yellow. This is because China rose indicator is an acid-base indicator that changes color in response to changes in pH.

Explanation:

A farmer may add quicklime and calcium oxide to their fields for a few reasons. One reason is to increase soil pH and reduce soil acidity, as crops grow better in slightly acidic to neutral soil. Quicklime can also improve soil structure and increase the availability of nutrients like phosphorus and potassium.

Explanation:

No, nitric acid cannot turn red litmus paper blue. Red litmus paper is used to test for the presence of acids and will turn blue in the presence of a base or an alkaline solution with a pH above 7. Nitric acid is a strong acid and will turn red litmus paper red or no change.

Explanation:

Antacids are basic compounds that neutralize stomach acid. If tested on a pH scale, they will fall above the seven pH category. They work by increasing the pH of the stomach contents, reducing the acidity that can cause discomfort and damage to the stomach lining.

Explanation:

Sodium hydroxide (NaOH) and hydrochloric acid (HCl) react to form sodium chloride (NaCl) and water (H2O) in a neutralization reaction. The balanced chemical equation for this reaction is NaOH + HCl → NaCl + H2O. This reaction is an example of an acid-base reaction, where the base (NaOH) reacts with the acid (HCl) to form a salt (NaCl) and water (H2O).

Explanation:

Methyl orange is an acid-base indicator that changes color in response to changes in pH. When used as an indicator, methyl orange will turn red in an acidic solution with a pH below 3.1, indicating that the solution is acidic. This is due to the chemical structure of methyl orange, which undergoes a reversible color change when the pH of the solution changes.

Explanation:

Excessive use of fertilizers by farmers can lead to various negative impacts on the soil and the crop. It can result in soil and water pollution, as the excess nutrients can leach into nearby water bodies and cause algal blooms. This can lead to the death of aquatic life and impact human health. Additionally, overuse of fertilizers can decrease soil fertility and increase greenhouse gas production. 

Explanation:

Three examples of strong acids are hydrochloric acid (HCl), sulfuric acid (H2SO4), and nitric acid (HNO3). Sulfuric acid is a strong and highly corrosive acid used in various industrial processes, including producing fertilizers, detergents, and dyes. It is also used in car batteries and as a laboratory reagent. 

Explanation:

Three examples of weak acids are acetic acid (CH3COOH), citric acid (C6H8O7), and formic acid (HCOOH). Acetic acid is a weak organic acid commonly found in vinegar and is used in food preservation and preparation. Acetic acid has a distinctive sour taste and pungent smell and can be used to produce various chemicals, including plastics and solvents. 

Explanation:

The acid present in car batteries is typically sulfuric acid (H2SO4). It is a highly corrosive and reactive acid that facilitates the chemical reaction that produces electrical energy in the battery.

Explanation:

One example of neutral salt is sodium chloride (NaCl), or table salt. It is considered neutral because it has an equal number of positive and negative ions, resulting in a net neutral charge. Sodium chloride has many applications, such as being used as a seasoning for food, in the production of chlorine and sodium hydroxide, and being added to water to create a saline solution for medical purposes.

Explanation:

The pH scale measures the acidity or basicity of a solution. It ranges from 0 to 14, with seven being neutral. Solutions with a pH below 7 are acidic, while solutions above 7 are basic or alkaline. Any solution with a pH value of 7 will be considered neutral. 

Explanation:

Acid rain has severe effects on humans as well as animals. It includes damage to monuments, buildings, offices, etc. It also affects plants and animals. Marine Life is majorly affected by acid rain. We can get saved from the effects of acid rain only if we reduce the acid rain; for that, we need to conserve energy.

Explanation:

Organic matter is added to the soil only when the soil has basic properties in it. Organic matter plays a major role here as it releases acids. The acid reacts with the base in the soil, thus neutralizing its effects. This process helps in protecting the soil. 

Explanation:

When a weak base like baking soda is added to water, it partially dissociates to release some hydroxide ions, but not enough to cause a change in the pH of the solution. This is why dry litmus paper does not change color when it comes into contact with solid baking soda.

Explanation:

A buffer solution is a solution that can resist changes in pH when small amounts of an acid or a base are added to it. It contains a weak acid and its corresponding conjugate base or a weak base and its corresponding conjugate acid. The buffer system can absorb any added hydrogen ions (H+) or hydroxide ions (OH-), thus preventing significant changes in the pH of the solution.

Explanation:

Strong acids and bases completely dissociate in water to form a high concentration of hydrogen ions (H+) or hydroxide ions (OH-), respectively. Weak acids and bases only partially dissociate in water, resulting in a lower H+ or OH concentration. Strong acids and bases are more reactive and have a higher potential to cause burns and other harmful effects. Weak acids and bases have a lower reactivity and are less harmful.

Explanation:

The strength of an acid or a base is directly related to its corrosive properties. Strong acids and bases have a higher potential to cause burns and other harmful effects on the skin and other materials due to their highly reactive nature. Weak acids and bases have a lower reactivity and are less corrosive.

Explanation:

An indicator is a substance that changes color depending on the pH of a solution. Indicators can be organic compounds that are weak acids or bases, such as litmus, phenolphthalein, and methyl orange. An indicator is added to a solution, and the resulting color change is compared to a color chart to determine the approximate pH of the solution. Different indicators are more suitable for different pH ranges, so the choice of an indicator depends on the expected pH of the solution being tested.

Explanation:

Acids react with most metals to produce salt and hydrogen gas. The reaction involves the transfer of electrons from the metal to the hydrogen ions in the acid. On the other hand, bases do not react with most metals, but some reactive metals, such as zinc and aluminum, will dissolve in strong bases to produce salt and hydrogen gas. These reactions are used in practical applications such as the production of hydrogen gas, the removal of rust, and the etching of metals.

Explanation:

Acids and bases are corrosive and can cause chemical burns, eye and skin damage, and respiratory problems if inhaled. They should be handled cautiously, and proper personal protective equipment should be worn. They should be stored in properly labeled containers, and any spills should be immediately neutralized and cleaned up. The disposal of acids and bases should follow proper procedures according to local regulations.

Explanation:

Salts affect the properties of water by lowering its freezing point and raising its boiling point. This is due to the disruption of the hydrogen bonds between water molecules by the ions in the salt, making it more difficult for the water to change its state. This effect is known as colligative properties.

Explanation:

The Arrhenius definition of an acid is a substance that produces hydrogen ions (H+) when dissolved in water, while a base produces hydroxide ions (OH-). The Bronsted-Lowry definition expands on this by defining an acid as a proton (H+) donor and a base as a proton acceptor. This definition includes substances that do not produce hydroxide ions in water, such as ammonia.

Explanation:

The dissociation constant (Ka for acids and Kb for bases) measures the degree to which an acid or a base dissociates in water. A higher Ka or Kb value indicates a stronger acid or base because it indicates a greater extent of ionisation. The pKa or pKb values are often used as a more convenient way of expressing the strength of an acid or base.

Explanation:

The pH scale measures the acidity or alkalinity of a solution. It is related to the solution's concentration of hydrogen ions (H+). A low pH indicates a high concentration of H+ ions, while a high pH indicates a low concentration of H+ ions. The pH scale ranges from 0 to 14, with seven being neutral.

Explanation:

Blue litmus turns red because of acid, while red litmus turns blue because of the base. Acids have a sour taste, while bases have a bitter taste. Acids feel sticky, while bases are slippery. Phenolphthalein remains colourless in an acidic solution, while it gives pink colour in a basic solution.

Explanation:

Bases feel soapy in touch and are bitter. Basic solutions are turned green by china rose, which is considered as an indicator. Phenolphthalein gives a pink colour in a basic solution. Bases are also slippery and odourless.

Explanation:

Acids are sour and feel slippery in touch. It produces a burning sensation. There is no change in colour with the turmeric indicator. It turns blue litmus to red. Phenolphthalein remains colourless when the solution is acidic.

Explanation:

When acid reacts with a base, it produces salt and water along with the evolution of heat. This reaction between acid and base is called a neutralisation-neutralisation reaction. An example of a neutralisation reaction is When hydrochloric acid reacts with sodium hydroxide; it gives sodium chloride and water along with the evolution of heat. 

Explanation:

Formic acid gets injected when an ant bites. So, this can be cured by applying base because it neutralises the effect and provides relief to us. An antacid like milk of magnesia can be used to fulfil this purpose. This base reacts with excess acids and neutralises the effect. Hence applying a base for ant bites is very useful.

Explanation:

Turmeric is a naturally occurring yellow compound, and yes, turmeric is a natural indicator as when it is added to a basic solution, it turns the yellow colour into pinkish-red colour while when added to an acidic solution, it remains in its yellow colour.