Engineering Chemistry DCH002A Exam

Common sterilization techniques include chlorination, UV radiation, and ozonation.

The octane number measures the resistance of gasoline to knocking during combustion.

The electrochemical series ranks elements based on their standard electrode potentials.

<p>Common methods include scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM).</p> Signup and view all the answers

<p>Examples include solar energy, wind energy, and hydroelectric power.</p> Signup and view all the answers

<p>Boiler troubles can include scaling, corrosion, and blowdown issues.</p> Signup and view all the answers

<p>Lubricants are substances that reduce friction between surfaces, and methods include oil lubrication and grease application.</p> Signup and view all the answers

<p>Atom economy measures the efficiency of a reaction in converting reactants to useful products, calculated as the ratio of molecular weight of desired products to the total molecular weight of reactants.</p> Signup and view all the answers

<p>Electrode potential is influenced by the concentration of ions in solution, temperature, and the type of electrode material used.</p> Signup and view all the answers

<p>The bottom-up approach involves assembling nanoparticles from atomic or molecular components through chemical reactions, often resulting in high purity and customizable properties.</p> Signup and view all the answers

<p>Sacrificial anodic protection involves attaching a more reactive metal to a less reactive metal, causing the sacrificial metal to corrode and protect the underlying metal.</p> Signup and view all the answers

<p>Nanotechnology promotes water purification through advanced filtration techniques, including nanoparticle-coated membranes and adsorbent materials that trap impurities.</p> Signup and view all the answers

<p>Oxidative corrosion involves an anodic reaction where metal loses electrons and a cathodic reaction where oxygen or other agents gain electrons, forming corrosion products.</p> Signup and view all the answers

<p>The protective oxide layer acts as a barrier that prevents further oxidation of the underlying material, significantly reducing corrosion rates.</p> Signup and view all the answers

<p>Nanomaterials can be classified as zero-dimensional (quantum dots), one-dimensional (nanowires), two-dimensional (nanoplates), and three-dimensional (nanoparticles).</p> Signup and view all the answers

<p>Scales are solid deposits that form on surfaces due to mineral precipitation, while sludges are semi-solid aggregates of suspended particles in water.</p> Signup and view all the answers

<p>Permanent hardness is caused primarily by the presence of dissolved calcium and magnesium sulfate or chloride in water.</p> Signup and view all the answers

<p>Liquid metal corrosion occurs when a metal comes into contact with a liquid metal, leading to degradation due to diffusion and other factors.</p> Signup and view all the answers

<p>Calorific value is the amount of energy produced by combustion of a unit quantity of fuel, usually expressed in calories or joules per gram.</p> Signup and view all the answers

<p>SEM (Scanning Electron Microscope) provides 3D images of samples' surfaces, while TEM (Transmission Electron Microscope) offers images of the internal structure at atomic resolution.</p> Signup and view all the answers

<p>Caustic embrittlement is the weakening of metals due to the presence of caustic soda at high temperatures, leading to stress corrosion cracking.</p> Signup and view all the answers

<p>Hot dipping involves coating a metal with molten zinc, while cementation is a surface treatment method that involves diffusion of carbon or other elements into a metal.</p> Signup and view all the answers

<p>A good fuel should have high calorific value, low ash content, ease of handling, and minimal environmental impact upon combustion.</p> Signup and view all the answers

<p>Top down involves breaking down bulk materials to nanostructures, while bottom up focuses on assembling nanoparticles from atoms or molecules.</p> Signup and view all the answers

<p>The flash point of a lubricant is the lowest temperature at which it can form an ignitable mixture in air. Its significance lies in determining the safety and storage requirements for lubricants.</p> Signup and view all the answers

<p>The fire point of a lubricant is the temperature at which it continues to burn for at least five seconds after ignition. It is important as it indicates the combustion characteristics and safety during application and handling.</p> Signup and view all the answers

<p>The water disinfection process using bleaching powder involves the addition of calcium hypochlorite to water, which releases chlorine to kill bacteria and pathogens. This method is significant for ensuring safe drinking water.</p> Signup and view all the answers

<p>Thin film lubrication is a lubrication regime where a continuous film of lubricant separates the surfaces in relative motion, minimizing direct contact. This reduces friction and wear, enhancing the lifespan of mechanical components.</p> Signup and view all the answers

<p>The molecular formula of zeolite generally can be represented as $AlSiO_{4}$, with varying amounts of water and cations. It plays a critical role in the ion-exchange process for water softening.</p> Signup and view all the answers

<p>The amount of lime ($Ca(OH)<em>{2}$) is calculated based on the calcium and magnesium hardness, while soda ($Na</em>{2}CO_{3}$) is calculated to eliminate residual hardness due to magnesium. Specific formulas and measured concentrations are applied for accurate calculations.</p> Signup and view all the answers

<p>The cloud point is the temperature at which wax or other insoluble components begin to crystallize in a lubricant, causing cloudiness. It is important for understanding the performance of lubricants in colder conditions.</p> Signup and view all the answers

<p>The neutralization number is a measure of the amount of acidic or basic substances present in a lubricant, typically expressed in mg of KOH required to neutralize 1 gram of sample. It signifies the lubricant’s degradation and its ability to protect metal surfaces.</p> Signup and view all the answers