Answer the following question given this paragraph: Molten Salts and Ionic Liquids Heating a salt to its melting point produces a molten salt. If we heated a sample of solid NaCl to its melting point of 801C, for example, it would melt to give a stable liquid that conducts electricity. The characteristics of molten salts other than electrical conductivity are their high heat capacity, ability to attain very high temperatures (over 700C) as a liquid, and utility as solvents because of their relatively low toxicity. Molten salts have many uses in industry and the laboratory. For example, in solar power towers in the desert of California, mirrors collect and focus sunlight to melt a mixture of sodium nitrite and sodium nitrate. The heat stored in the molten salt is used to produce steam that drives a steam turbine and a generator, thereby producing electricity from the sun for southern California. Due to their low toxicity and high thermal efficiency, molten salts have also been used in nuclear reactors to enable operation at temperatures greater than 750C. One prototype reactor tested in the 1950s used a fuel and a coolant consisting of molten fluoride salts, including NaF, ZrF 4, and UF4. Molten salts are also. Q: Ionic liquids heating a salt to its melting point produces a what? Choices: - table salt - plasma - gas - molten salt A:
molten salt
(Question)
Answer the following question given this paragraph: Most flowers carry both stamens and carpels; however, a few species self-pollinate. These are known as "perfect" flowers because they contain both types of sex organs (Figure 14.25. Biochemical and anatomical barriers to self-pollination promote cross-pollination. Self-pollination is a severe form of inbreeding, and can increase the number of genetic defects in offspring. A plant may have perfect flowers, and thus have both genders in each flower; or, it may have imperfect flowers of both kinds on one plant (Figure 14.28). In each case, such species are called monoecious plants, meaning "one house. " Some botanists refer to plants with perfect flowers simply as hermaphroditic. Some plants are dioecious, meaning "two houses," and have male and female flowers ("imperfect flowers") on different plants. In these species, cross-pollination occurs all the time. Q: Most flowers carry both stamens and carpels; however, a few species are capable of what and are nicknamed "perfect" flowers? Choices: - sexual reproduction - germination - cloning - self-pollination A:
(Answer)
self-pollination
Ques: Answer the following question given this paragraph: The skeleton supports the body, protects internal organs, produces blood cells, and maintains mineral homeostasis. Q: What structure supports the body, protects internal organs, produces blood cells, and maintains mineral homeostasis? Choices: - fossil - skin - cuticle - skeleton A:
Ans: skeleton
(Q).
Answer the following question given this paragraph: The frequency factor is used to convert concentrations to collisions per second. Equation 14.39 is known as the Arrhenius equation and summarizes the collision model of chemical kinetics, where T is the absolute temperature (in K) and R is the ideal gas constant [8.314 J/(Kmol)]. Ea indicates the sensitivity of the reaction to changes in temperature. The reaction rate with a large Ea increases rapidly with increasing temperature, whereas the reaction rate with a smaller Ea increases much more slowly with increasing temperature. If we know the reaction rate at various temperatures, we can use the Arrhenius equation to calculate the activation energy. Taking the natural logarithm of both sides ofEquation 14.39, Equation 14.40. Q: What is used to convert concentrations to collisions per second? Choices: - speeds factor - collision meter - particles factor - frequency factor A:
(A).
frequency factor
Ques:Answer the following question given this paragraph: As indicated in http://catalog. flatworldknowledge. com/bookhub/reader/2547 - gob-ch10_s04, weak acids are relatively common, even in the foods we eat. But we occasionally come across a strong acid or base, such as stomach acid, that has a strongly acidic pH of 12. By definition, strong acids and bases can produce a relatively large amount of hydrogen or hydroxide ions and, as a consequence, have a marked chemical activity. In addition, very small amounts of strong acids and bases can change the pH of a solution very quickly. If 1 mL of stomach acid [which we will approximate as 0.05 M HCl(aq)] is added to the bloodstream, and if no correcting mechanism is present, the pH of the blood would go from about 7.4 to about 4.9a pH that is not conducive to continued living. Fortunately, the body has a mechanism for minimizing such dramatic pH changes. The mechanism involves a buffer, a solution that resists dramatic changes in pH. Buffers do so by being composed of certain pairs of solutes: either a weak acid plus a salt derived from that weak acid or a weak base plus a salt of that weak base. For example, a buffer can be composed of dissolved acetic acid (HC2H3O2, a weak acid) and sodium acetate (NaC2H3O2, a salt derived from that acid). Another example of a buffer is a solution containing ammonia (NH3, a weak base) and ammonium chloride (NH4Cl, a salt derived from that base). Let us use an acetic acidsodium acetate buffer to demonstrate how buffers work. If a strong basea source of OH(aq) ionsis added to the buffer solution, those hydroxide ions will react with the acetic acid in an acid-base reaction: HC2H3O2(aq) + OH(aq) H2O() + C2H3O2(aq) Rather than changing the pH dramatically by making the solution basic, the added hydroxide ions react to make water, and the pH does not change much. Q: Acids are associated with a low number on which scale? Choices: - metric - acidic - ionic - ph A:

Ans:ph
Answer the following question given this paragraph: We know that the Universe is expanding. Astronomers have wondered if it is expanding fast enough to escape the pull of gravity. Would the Universe just expand forever? If it could not escape the pull of gravity, would it someday start to contract? This means it would eventually get squeezed together in a big crunch. This is the opposite of the Big Bang. Q: Astronomers have wondered if the universe is expanding fast enough to escape the pull of what? Choices: - kinetic energy - Coreolis effect - light - gravity A:
gravity