GRE Vocab 011-30- Ielts Resources

Question 1

lubrication of pumps

Answer 1

• Pump lubrication refers to the process of supplying oil or grease to the moving parts of a pump. This lubricating fluid offsets friction in bearings, preventing wear and tear and enhancing the pump’s efficiency.
• Proper lubrication of pumps is crucial for extending bearing life and ensuring smooth operation.
• Filtering new lubricating oils to remove particles and maintaining low moisture levels are essential practices in effective pump lubrication.
• Without adequate lubrication, pumps are more likely to fail prematurely due to increased wear and reduced effectiveness

Question 2

compressors

Answer 2

• A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. It’s akin to an air pump, but its primary focus is altering the density or volume of gases, making it ideal for compressible substances like air.
• In industrial settings, reciprocating compressors play a vital role by pressurizing gases for various applications.
• High-pressure breathing air compressors are essential for filling scuba cylinders, ensuring safe underwater exploration.
• Unlike liquids, which are relatively incompressible, compressors excel at handling gases due to their inherent compressibility

Question 3

valves

Answer 3

• A valve is a device or natural object that regulates, directs, or controls the flow of fluids (such as gases, liquids, or slurries). It achieves this by opening, closing, or partially obstructing various passageways. Valves are commonly used in engineering, biology, and music.
• In plumbing systems, water valves control the flow of water to different fixtures in a building.
• The heart valves play a crucial role in maintaining blood flow by opening and closing rhythmically.
• Trumpet valves alter the pitch and tone of the instrument by regulating the flow of air through the tubing

Question 4

catalytic

Answer 4

• Catalytic refers to something related to catalysis, which is the process of speeding up a chemical reaction using a substance that is not consumed in the reaction
• Catalytic converters in cars reduce harmful emissions by facilitating chemical reactions.
• Enzymes act as catalytic agents in biological processes, accelerating vital reactions.
• Selective catalytic reduction systems help power plants minimize pollution

Question 5

catalytic cracking

Answer 5

• Catalytic cracking is a process used in petroleum refineries to convert high-boiling point hydrocarbon fractions into gasoline, alkene gases, and other petroleum products. It involves breaking down complex hydrocarbons into simpler molecules by using a catalyst.
• Catalytic cracking enhances the quality and quantity of lighter, more desirable products while decreasing residuals.
• Modern refineries employ fluid catalytic cracking units to produce high-octane gasoline.
• Unlike thermal cracking, which was previously used, catalytic cracking yields valuable by-product gases with greater economic value

Question 6

containing zeolites

Answer 6

• Zeolites are a family of microporous, crystalline aluminosilicate materials commonly used as commercial adsorbents and catalysts. They mainly consist of silicon, aluminum, oxygen
• Zeolites containing water can be driven off by heat, leaving voids that serve various purposes, including ion exchange, filtering, and odor removal.
• Catalytic converters often utilize zeolites to facilitate chemical reactions and reduce harmful emissions.
• In water softeners, the best-known application, zeolites efficiently remove hardness ions from water

Question 7

alumina types

Answer 7

• Alumina refers to aluminum oxide, a chemical compound with the formula Al₂O₃. It is commonly used in various forms and applications, including as an abrasive, refractory material, and catalyst
• Smelter-grade alumina plays a crucial role in aluminum production.
• Calcined alumina is used in ceramics and electrical insulation.
• High-purity alumina serves as a raw material for advanced ceramic products

Question 8

thermal cracking

Answer 8

• Thermal cracking involves breaking large hydrocarbon molecules into smaller ones using high temperatures and pressures. It results in mixtures rich in alkenes (hydrocarbons with double bonds).
• Thermal cracking is used to produce naphtha, gas oil, and coke in refining processes.
• At temperatures of 450°C to 750°C, thermal cracking alters hydrocarbon structures.
• The outcome includes valuable alkenes, essential for various industrial applications

Question 9

heavy distillates

Answer 9

• Heavy distillates refer to liquid hydrocarbons that are recovered from crude petroleum during the distillation process. These include heavy fuel oil, lubricating oils, wax, and asphalt.
• Heavy distillates find use in industrial applications, such as powering ships and generating heat.
• Lubricating oils, a type of heavy distillate, ensure smooth machinery operation.
• Asphalt, another heavy distillate, is commonly used for road construction

Question 10

hydrogen separated out

Answer 10

• Hydrogen separated out refers to the process of extracting hydrogen gas (H₂) from water (H₂O). This separation is crucial for harnessing hydrogen as a clean and sustainable energy resource.
• Water electrolysis achieves hydrogen separation by inducing separate “evolution reactions” for hydrogen and oxygen molecules using electrodes and a catalyst.
• Researchers have discovered efficient, low-cost catalysts for oxygen molecules, enabling commercial-scale hydrogen extraction from water
• The quest for better hydrogen separation methods continues, aiming to meet global energy demands sustainably

Question 11

redistillation

Answer 11

• Redistillation refers to the process of distilling a liquid again (making it stronger or purer by heating until it changes to a gas and then cooling it back into a liquid), often for a second, third, or subsequent time.
• The alcohol is collected for redistillation to enhance its purity.
• Re-distillation is a convenient and cost-effective method for recovering valuable oils.
• In the pursuit of purity, redistillation corrects the toxicity of ordinary distilled water

Question 12

catalyst in pellets

Answer 12

• Catalyst in pellets refers to catalytic materials that are shaped into small, solid pellets. These pellets are used in various applications, such as chemical reactions, refining processes, and environmental control.
• Catalyst pellets enhance chemical reactions by providing a high surface area for interaction.
• Fluidized bed reactors often employ catalyst pellets for efficient gas-solid interactions.
• Zeolites in pellet form are common examples of catalyst pellets

Question 13

residuum

Answer 13

• Residuum refers to the residue, remainder, or rest of something. In chemistry, it can also denote a solid material remaining after evaporation, combustion, or distillation.
• Even highly decaffeinated coffee contains a tiny residuum of caffeine.
• In plain, spare prose, John Hersey documents scenes of unprecedented ruin, capturing the ghostly residuum of calamity.
• Residuum often lingers, hinting at what was once present but now remains as a faint echo

Question 14

catalytic cracking

Answer 14

• Catalytic cracking is the process used in petroleum refineries to convert high-boiling point hydrocarbon fractions into gasoline, alkene gases, and other petroleum products. It involves breaking down complex hydrocarbons into simpler molecules using a catalyst.
• Catalytic cracking enhances gasoline production by breaking down heavy hydrocarbons.
• Modern refineries rely on fluid catalytic cracking units for efficient conversion.
• Unlike thermal cracking, which was previously used, catalytic cracking yields valuable by-product gases with greater economic value

Question 15

plunged into Jupiter

Answer 15

• To plunge into Jupiter means to descend rapidly into Jupiter’s atmosphere. It often refers to spacecraft or probes intentionally entering the gas giant’s outer layers for scientific exploration.
• The Galileo spacecraft bravely plunged into Jupiter to gather data about its composition and magnetic field.
• Scientists carefully planned the trajectory to ensure that Galileo would not survive the intense heat as it plunged into Jupiter.
• On September 21, 2003, Galileo plunged into Jupiter’s atmosphere to prevent an unwanted impact with Europa, one of Jupiter’s moons

Question 16

tremendous

Answer 16

• Tremendous means very great in amount, scale, or intensity. It can also describe something extremely good or impressive.
• The team’s effort resulted in a tremendous victory.
• The impact of climate change is tremendous and requires urgent action.
• Her dedication to the project was tremendous and greatly appreciated

Question 17

comet

Answer 17

• A comet is an object in the solar system made of ice and dust that looks like a bright star with a tail when near the sun
• Halley’s Comet is visible from Earth every 75–79 years.
• Skywatchers have chances to glimpse the comet through most of the remainder of the month.
• In 1994, a comet broke apart and plunged into Jupiter, ripping holes the size of Earth in the planet’s atmosphere.

Question 18

asteroid

Answer 18

• An asteroid is a big rock in space. It orbits the Sun and can vary in size from small pebbles to large bodies.
• Most asteroids are found between Mars and Jupiter.
• The spacecraft brought back a sample from the asteroid Bennu.
• An asteroid as large as 300 feet wide will fly between Earth and the moon

Question 19

comet tend

Answer 19

• A comet is a celestial object composed of ice, dust, and other organic compounds, which orbits the sun in a highly elliptical path. It often develops a glowing coma, or a hazy cloud, and a tail when it approaches the sun.
• The comet streaked across the night sky, leaving a mesmerizing trail behind.
• Astronomers eagerly observed the comet’s trajectory as it approached the sun.
• Her intellect and wit shone as bright as a comet, captivating everyone in the room1.

Question 20

carbon monoxide

Answer 20

• Carbon monoxide is a colorless, odorless, toxic flammable gas formed by incomplete combustion of carbon. It is produced by vehicles and heating equipment that is not working properly.
• Carbon monoxide poisoning can occur when this gas accumulates in enclosed spaces.
• Exposure to carbon monoxide can lead to headaches, dizziness, and even death.
• Proper ventilation and regular maintenance are essential to prevent carbon monoxide buildup

Question 21

icy comet vaporizes

Answer 21

• An icy comet is a celestial object composed of frozen gases and dust. As it approaches the Sun, the heat causes the icy nucleus to vaporize, creating a glowing coma (cloud of gas and dust) and a tail that points away from the Sun due to solar wind
• Comets, with their icy composition, captivate astronomers and skywatchers alike.
• As a comet vaporizes, it leaves behind a luminous trail visible from Earth.
• The tail of an icy comet reveals its journey through the solar system

Question 22

ammonia

Answer 22

• Ammonia is a colorless gas with a characteristic pungent smell. It dissolves in water to give a strongly alkaline solution. It is used in making explosives, fertilizers, and some cleaning products
• The pungent smell of ammonia filled the laboratory.
• Ammonia is commonly used as a cleaning agent.
• Proper ventilation and regular maintenance are essential to prevent carbon monoxide buildup

Question 23

hydrogen sulfide

Answer 23

• Hydrogen sulfide is a colorless, flammable, water-soluble, cumulatively poisonous gas (H₂S) that has an odor suggestive of rotten eggs. It is found especially in many mineral waters and in putrefying matter
• Hydrogen sulfide can be lethal in high concentrations and is often characterized by its foul smell.
• The lake’s hydrogen sulfide levels were measured at 0.3 parts per million.
• Testing for hydrogen sulfide is crucial in ensuring safety and preventing exposure

Question 24

sulfur gas

Answer 24

• Sulfur gas refers to gaseous compounds containing sulfur, such as hydrogen sulfide (H₂S). These gases often have a strong, unpleasant odor and can be toxic.
• The air near the volcanic vent reeked of sulfur gas.
• Hydrogen sulfide, a common sulfur gas, is produced in swamps and sewage systems.
• Proper ventilation is crucial to prevent exposure to harmful sulfur gases

Question 25

astroids

Answer 25

• An asteroid is a big rock in space. It orbits the Sun and can vary in size from small pebbles to large bodies.
• Most asteroids are found between Mars and Jupiter.
• The spacecraft brought back a sample from the asteroid Bennu.
• An asteroid as large as 300 feet wide will fly between Earth and the moon

Question 26

rockier

Answer 26

• Consisting of or abounding in rocks: A rockier shore is one with more rocks.
• Hard or unyielding: His rockier determination kept him going.
• Weak, shaky, or unstable: After the fall, she felt rockier and nauseated
• The journey through the mountains became rockier as they ascended.
• The rockier parts of the trail required careful footing.
• Their relationship hit a rockier patch, but they worked through it

Question 27

halo or a tail

Answer 27

Halo :

A halo can refer to a luminous ring or circle around the sun or moon caused by the refraction or scattering of light through ice crystals in the atmosphere.
It can also metaphorically represent a glowing or revered quality associated with someone or something.

• The gassy halo means that the area could form clusters of stars

Tail :

A tail is the rear part of an animal’s body, typically used for balance, communication, or propulsion.
It can also metaphorically refer to the trailing part of a story or event.

• The dog wags its tail when happy.
• The cat’s tail helps it balance on the wall.
• The peacock has a beautiful long tail

Question 28

fragile asteroid

Answer 28

• A fragile asteroid refers to an asteroid with a weak or loosely bound structure, making it prone to breaking apart or disintegrating.
• The fragile asteroid shattered upon entering Earth’s atmosphere.
• Scientists study fragile asteroids to understand their composition and behavior.
• The fragile asteroid’s tail of debris spread across the sky during its breakup