Hygroscopic Definition in Chemistry

Water is an important solvent, so its unsurprising that there is a term specifically related to water absorption. A hygroscopic substance is able to absorb or adsorb water from its surroundings. Typically, this occurs at or near ordinary room temperature. Most hygroscopic materials are salts, but many other materials display the property. How it Works When water vapor is absorbed, the water molecules are taken into the molecules of the hygroscopic substance, often resulting in physical changes, such as increased volume. Color, boiling point, temperature, and viscosity can also change. In contrast, when water vapor is adsorbed, the water molecules remain on the surface of the material. Examples of Hygroscopic Materials Zinc chloride, sodium chloride, and sodium hydroxide crystals are hygroscopic, as are silica gel, honey, nylon, and ethanol.Sulfuric acid is hygroscopic, not only when concentrated but also when reduced down to a concentration of 10% v/v or even lower.Germinating seeds are hygroscopic. After seeds have dried, their outer coating becomes hygroscopic and begins absorbing the moisture required for germination. Some seeds have hygroscopic portions that cause the shape of the seed to change when moisture is absorbed. The seed of Hesperostipa comata twists and untwists, depending on its hydration level, drilling the seed into the soil.Animals can also have characteristic hygroscopic properties. For example, a species of lizard commonly called the thorny dragon has hygroscopic grooves between its spines. Water (dew) condenses on the spines at night and collects in the grooves. The lizard is then able to distribute water across its skin by means of capillary action. Hygroscopic vs. Hydroscopic You might encounter the word hydroscopic used in place of hygroscopic, however, while hydro- is a prefix meaning water, the word hydroscopic is a misspelling and is incorrect. A hydroscope is an instrument used to take deep-sea measurements. A device called a hygroscope in the 1790s was an instrument used to measure humidity levels. The modern name for such a device is a hygrometer. Hygroscopy and Deliquescence Hygroscopic and deliquescent materials are both able to absorb moisture from the air. However, hygroscopy and deliquescence dont mean precisely the same thing: Hygroscopic materials absorb moisture, while deliquescent materials absorb moisture to the extent that the substance dissolves in water. A hygroscopic material will become damp and may stick to itself or become caky, while a deliquescent material will liquefy. Deliquescence may be considered an extreme form of hygroscopy. Hygroscopy vs. Capillary Action While capillary action is another mechanism involving the uptake of water, it differs from hygroscopy in that no absorption occurs in the process. Storing Hygroscopic Materials Hygroscopic chemicals require special care. Typically, they are stored in airtight containers. They may also be maintained under kerosene, oil, or within a dry atmosphere. Uses of Hygroscopic Materials Hygroscopic substances are used to keep products dry or to remove water from an area. They are commonly used in desiccators. Hygroscopic materials may be added to products due to their ability to attract and hold moisture. These substances are referred to as humectants. Examples of humectants used in food, cosmetics, and drugs include salt, honey, ethanol, and sugar. The Bottom Line Hygroscopic and deliquescent materials and humectants are all able to absorb moisture from the air. Generally, deliquescent materials are used as desiccants. They dissolve in the water they absorb to yield a liquid solution. Most other hygroscopic materials—which dont dissolve—are called humectants.

The Importance Of Faulkners Nobel Peace Prize Acceptance...

What defines a writer and their ability to deliver a message? Is it their level of eloquence? Or is it the topic that they decided to dedicate their time to writing about? To simply answer, yes and yes. Being a writer does require all of the above, but it necessitates something more. It requires the passion and ardor that one has to bring into their writing. In a time of fear and anguish, most might lose that passion that sparked in them, leaving behind a passionless and hopeless shell. In his Nobel Peace Prize acceptance speech at the Nobel Banquet, these were the issues William Faulkner had to address. Using his platform for something greater, Faulkner delivered his speech, not only to accept his award but to advise the future†¦show more content†¦To the future generations of writers that Faulkner was speaking to, they would fulfill his wishes. Over 50 years later, University of Chicago economist, Steven D. Levitt, and New York Times journalist, Stephen J. Dubner, combined their knowledge and skills and created the book, Freakonomics. The book follows an economist, Levitt, as he explores the â€Å"hidden side of everything† and explains it all in a different, unconventional perspective. It takes on the topic of morality and economics as he, along with Dubner, ask and answer many questions such as, which is more dangerous, a gun or a swimming pool? What do schoolteachers and sumo wrestlers have in common? Or why do drug dealers still live with their moms? As the reader can see, these questions aren’t the usual conventional ones. It takes on an unprecedented vi ew as Levitt and Dubner research and give a whole new perspective on how the world works. As they answer these unconventional questions, it show the consideration, thoughtfulness, and research that Levitt and Dubner went through in order to give the proper answer. Yet not only do they give the answers but they give a thorough explanation as they navigate the readers through their entire thinking process, showing the passion and deliberation that they put into making this book. Consider the question that Levitt and Dubner asked in chapter five, which is more dangerous, a gun or a swimming pool? MostShow MoreRelatedLogical Reasoning189930 Words   |  760 Pagesmention the word â€Å"declarative.† Also, we usually don’t use the word â€Å"logically.† ────CONCEPT CHECK──── Create two sentences about basketball that are inconsistent with each other. ────5 Examples of Good Reasoning So far weve explored the importance of reasoning logically in situations that require a decision—either a decision about what to do or a decision about what to believe. Along the way weve introduced a variety of rules of thumb for good reasoning, that is, high-quality reasoning

Functionalist view on the family free essay sample

In this essay the functionalist’s perspective will be examined on their viewpoint of the family. Also Marxists, feminists and new rights perspective will be taken into consideration. The overall functionalist theory on the family is that it performs positive functions for individuals and society. One of the most influential functionalists was Talcott parson whose understanding of the family was that it provides the primary socialisation of children, which means to teach the culture of society to the child. Another of his perspectives on the family was that it stabilises the adult personalities of the population of the society, which means that family life provides adults with emotional security that they need. However Marxists such as Althusser and Poulantzas counter attack this theory stating that families are reproducing capitalists and socialising pro-capitalist ideology to the children saying that hierarchy and inequality are inevitable. One Marxist called Freidrich Engels had a perspective on families that they were created when people started to value property, therefore men made sure they had sons to pass property down the family line. We will write a custom essay sample on Functionalist view on the family or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page This links to Althusser and Poulantzas theory that families have an ideology of capitalism and one of the ways to fulfil capitalism is through inheritance of property as Engels has mentioned. Engels also mentioned that this ideology of inheritance of property has turned women into mere instruments for the production of children. However a functionalist such as Murdock would reject Engels perspective because he believed that the functions of the family was to maintain sexual stability in society, provide society with new members, strengthen the bond between spouses and provide a division of labour and finally parents having the responsibilities to teach children social norms and way of life. Marxist feminists argue that the main cause of women’s oppression in the family is not men but capitalism and that the family reproduces patriarchy. A Marxist feminist called Margaret Benston believed that the family provides the basic commodities for capitalism such as labour power in which women reproduce the next workforce with little cost to the capitalism class. The women are a ‘reserve army’ of cheap labour. Fran Ansley has also stated that women are the ‘takers of shit’ which links to that women absorb anger. However feminists in general have been criticised about their perspectives because they do not account for the economic and  social changes such as more women having a job in the economy compared to in the 1950’s. They are also criticised for not observing the positive side of the family some women may want to raise children and run/control a home. New right perspective on the family is that they believe the government is weakening the family’s self-reliance by giving out welfare benefits. New right link this to raising crime rates in young people because the growth of lone parent families increase in popularity due to increased benefits therefore young children will grow up without a male/female role model which therefore leads to rising crime rates in young males and females. However feminists say that new right want to bring back a traditional nuclear family which they believe keeps women confined to a domestic role. In summary the analysis of the perspective of the family has many theories which can be argued however all the structural perspectives have the functions to which they believe a family fulfils.