Water Hardness and Treatment Quiz

<p>Lime soda process (C)</p> Signup and view all the answers

<p>Temporary Hardness + Permanent Hardness (C)</p> Signup and view all the answers

<p>Presence of sulphates (D)</p> Signup and view all the answers

<p>Calcium chloride and magnesium sulphate (A)</p> Signup and view all the answers

<p>Its molecular weight is a whole number (B)</p> Signup and view all the answers

<p>They can be recharged by passing electricity. (C)</p> Signup and view all the answers

<p>Lead acid storage battery (D)</p> Signup and view all the answers

<p>Lead (Pb) (C)</p> Signup and view all the answers

<p>Pb2+ ions (D)</p> Signup and view all the answers

<p>PbSO4 (A)</p> Signup and view all the answers

<p>Rubber or glass fiber (C)</p> Signup and view all the answers

<p>20% H2SO4 (B)</p> Signup and view all the answers

<p>It is reduced to Pb2+ ions. (C)</p> Signup and view all the answers

<p>2Fe + 2 H2O + O2 → 2 Fe(OH)2 (B)</p> Signup and view all the answers

<p>Hydrazine (A)</p> Signup and view all the answers

<p>Mechanical deaeration (A)</p> Signup and view all the answers

<p>Steel blue (B)</p> Signup and view all the answers

<p>Decreases (B)</p> Signup and view all the answers

<p>To reduce the volume to concentrate impurities (A)</p> Signup and view all the answers

<p>Desalination (C)</p> Signup and view all the answers

<p>Buffer solution and EBT indicator (A)</p> Signup and view all the answers

<p>CO2 + H2O → H2CO3 (D)</p> Signup and view all the answers

<p>The hardness has been fully titrated (A)</p> Signup and view all the answers

<p>1000 ppm (A)</p> Signup and view all the answers

<p>Adding required amount of NH4OH (C)</p> Signup and view all the answers

<p>Carbon dioxide (C)</p> Signup and view all the answers

<p>They remain unstable and wine red (D)</p> Signup and view all the answers

<p>Evaporation (D)</p> Signup and view all the answers

<p>20 ml (D)</p> Signup and view all the answers

<p>By using a semi-permeable membrane under pressure (C)</p> Signup and view all the answers

<p>Forms carbonic acid with a corrosive effect (D)</p> Signup and view all the answers

<p>It has more than 1000 ppm to less than 35000 ppm of dissolved solids (B)</p> Signup and view all the answers

<p>EBT (Eriochrome Black T) (B)</p> Signup and view all the answers

<p>Osmotic pressure (A)</p> Signup and view all the answers

<p>EDTA has reacted completely (C)</p> Signup and view all the answers

<p>Cellulose acetate (A)</p> Signup and view all the answers

<p>It contains more than 35000 ppm of dissolved solids (A)</p> Signup and view all the answers

<p>Li+ and e- (B)</p> Signup and view all the answers

<p>3.0V (B)</p> Signup and view all the answers

<p>Solid state constituents (D)</p> Signup and view all the answers

<p>Higher efficiency (B)</p> Signup and view all the answers

<p>Hydrogen is oxidized to water (A)</p> Signup and view all the answers

<p>Carbon with a catalyst (D)</p> Signup and view all the answers

<p>Methanol (C)</p> Signup and view all the answers

<p>To facilitate the oxidation and reduction reactions (D)</p> Signup and view all the answers

The dissolved salts in hard water react with the dyes, forming precipitates. This leads to wastage of dyes and affects the quality of the final product.

The dissolved salts in hard water can interfere with the crystallization process, making it difficult to obtain pure sugar crystals. This results in lower-quality sugar and reduced efficiency.

Hard water can affect the quality of paper. The dissolved salts can react with the paper fibers, leading to weaker, discolored, and less durable paper. This can be problematic in industries that rely on high-quality paper.

Hard water can cause the formation of undesirable products, affecting the purity and effectiveness of medications. This can impact the pharmaceutical industry's production of drugs and other products.

Temporary hardness is caused by the presence of dissolved bicarbonates of calcium and magnesium. It is called temporary because it can be removed through boiling or by adding lime to the water.

Permanent hardness is caused by dissolved chlorides and sulfates of calcium, magnesium, iron, and other metals. It is called permanent because it cannot be removed by boiling. It requires methods like the lime soda process or the zeolite process.

The concentration of hardness-causing salts is often expressed as an equivalent amount of CaCO3. This standard is used because CaCO3 is insoluble and its molecular weight makes calculations simpler.

The total hardness of water is the sum of temporary hardness and permanent hardness.

A complex formed between calcium ions (Ca2+) and Eriochrome Black T (EBT) indicator. It is unstable and appears wine red in color.

A complex formed between magnesium ions (Mg2+) and Eriochrome Black T (EBT) indicator. Like the Ca-EBT complex, it is also unstable and appears wine red.

A complex formed between calcium ions (Ca2+) and EDTA (ethylenediaminetetraacetic acid). This complex is stable and colorless.

A complex formed between magnesium ions (Mg2+) and EDTA (ethylenediaminetetraacetic acid). This complex is also stable and colorless.

The process of determining the exact concentration of a solution, such as EDTA, by reacting it with a known amount of a standard substance.

The total amount of calcium and magnesium ions present in a water sample. It is measured by titrating the water sample with a standardized EDTA solution.

The hardness of water caused by dissolved calcium and magnesium salts that remain even after boiling. This is also known as non-carbonate hardness.

A type of chemical indicator used in complexometric titrations. It changes color in the presence of calcium and magnesium ions, indicating the endpoint of the titration.

Dissolved oxygen in boiler water reacts with iron to form rust. This reaction is accelerated at high temperatures, leading to corrosion of boiler materials.

To remove dissolved oxygen from boiler water, chemical methods like adding sodium sulfite, hydrazine, or sodium sulfide are employed. These chemicals react with the oxygen, preventing it from causing corrosion.

Hydrazine is considered an ideal compound for removing dissolved oxygen because it forms water and inert nitrogen gas, which don't harm the boiler.

Mechanical deaeration involves using a tower to remove dissolved gases, including oxygen and carbon dioxide. Water is sprayed through perforated plates under reduced pressure and heated. This encourages the gases to leave the water, preventing corrosion.

Dissolved carbon dioxide in boiler water forms carbonic acid, which slowly corrodes boiler materials. Bicarbonate salts also release carbon dioxide when they are heated, further contributing to corrosion.

To remove dissolved carbon dioxide, ammonia (NH4OH) can be added to the water. This neutralizes the carbonic acid and prevents corrosion.

The solubility of a gas in a liquid is directly proportional to pressure and inversely proportional to temperature. In mechanical deaeration, high temperature and low pressure decrease oxygen solubility in water, promoting its removal.

The solubility of gases in water decreases with increasing temperature. That's why deaeration is often performed at high temperatures, driving off dissolved gases like oxygen and carbon dioxide.

The process of removing dissolved salts from water, often used to make seawater or brackish water drinkable.

Water with a salty or brackish taste, unsuitable for drinking due to high salt content.

A type of membrane used in reverse osmosis that allows water molecules to pass through while blocking dissolved salts.

The pressure difference between two solutions separated by a semi-permeable membrane, driving the movement of water from a dilute solution to a concentrated solution.

A process that forces water through a semi-permeable membrane from a concentrated solution to a dilute solution by applying pressure greater than the osmotic pressure.

A method of desalination where an electric current is applied to separate dissolved salts from water using ion-selective membranes.

Water containing less than 1000 ppm of dissolved solids, suitable for drinking.

A membrane filtration technique that uses a semi-permeable membrane to separate water molecules from dissolved salts and other impurities.

A type of battery that can be recharged by passing electricity through it, reversing the chemical reactions that occur during discharge.

A primary battery cannot be recharged, while a secondary battery can.

A lead-acid battery is a type of secondary battery that uses lead and lead dioxide as electrodes in an electrolyte solution of sulfuric acid.

In a lead-acid battery, during discharge, lead is oxidized to lead sulfate at the anode, while lead dioxide is reduced to lead sulfate at the cathode.

In a lead-acid battery, during charging, the lead sulfate at both electrodes is converted back to lead and lead dioxide.

The process of using a lead-acid battery as a voltaic cell involves converting chemical energy into electrical energy, while using it as an electrolytic cell means converting electrical energy into chemical energy during recharging.

A lead-acid battery is made up of several cells connected in series. Each cell has lead plates as anodes and lead dioxide plates as cathodes, immersed in sulfuric acid.

The density of the electrolyte solution in a lead-acid battery can be used to determine the state of charge. A higher density indicates a higher charge level.

A chemical reaction that occurs in a lithium battery when it is discharging (releasing energy). Lithium atoms lose an electron and become lithium ions (Li+), which move from the anode (negative electrode) to the cathode (positive electrode). The cathode accepts the electrons and gains lithium ions, forming a lithium-containing compound (for example, LiTiS2).

A chemical reaction that occurs during the recharging of a lithium battery. Lithium ions (Li+) move from the cathode back to the anode. The energy needed to drive this process is supplied by an external current source.

A device that directly converts chemical energy (from a fuel's oxidation) into electrical energy. It's more efficient than conventional systems that involve multiple energy conversions (thermal to mechanical, then mechanical to electrical).

A fuel cell that uses hydrogen as the fuel and oxygen as the oxidant. The reaction between hydrogen and oxygen produces electricity and water.

The electrodes in a fuel cell. The anode is where the fuel is oxidized, releasing electrons. The cathode is where the oxidant is reduced, accepting the electrons.

An electrolyte solution in a fuel cell that allows the movement of ions (charged particles) between the anode and cathode. This facilitates the electrochemical reaction.

The chemical process where a substance loses electrons, gaining a more positive oxidation state. In a fuel cell, the fuel is oxidized at the anode.

The chemical process where a substance gains electrons, becoming more negatively charged. In a fuel cell, the oxidant (often oxygen) is reduced at the cathode.