Answer the following question given this paragraph: The rate of breathing is regulated by the brain stem. It monitors the level of carbon dioxide in the blood and triggers faster or slower breathing as needed to keep the level within a narrow range. Q: Which part of the brain regulates the rate of breathing? Choices: - brain stem - brain uptake - brain charge - brain stem A:
brain stem
Answer the following question given this paragraph: Elements are represented by an atomic symbol. Q: An atomic symbol is used to represent what? Choices: - electron shell - mole - weight - element A:
element
Q: Answer the following question given this paragraph: (b) Write a balanced chemical equation showing the products of the dissolution of Fe(NO3)3. Compare the processes that occur when methanol (CH3OH), hydrogen chloride (HCl), and sodium hydroxide (NaOH) dissolve in water. Write equations and prepare sketches showing the form in which each of these compounds is present in its respective solution. What is the expected electrical conductivity of the following solutions? (a) NaOH(aq) (b) HCl(aq) (c) C6H12O6(aq) (glucose) (d) NH3(l) 14. Why are most solid ionic compounds electrically nonconductive, whereas aqueous solutions of ionic compounds are good conductors? Would you expect a liquid (molten) ionic compound to be electrically conductive or nonconductive? Explain. Indicate the most important type of intermolecular attraction responsible for solvation in each of the following solutions: (a) the solutions in Figure 11.8 (b) methanol, CH3OH, dissolved in ethanol, C2H5OH (c) methane, CH4, dissolved in benzene, C6H6 (d) the polar halocarbon CF2Cl2 dissolved in the polar halocarbon CF2ClCFCl2 (e) O2(l) in N2(l) 11.3 Solubility 16. Suppose you are presented with a clear solution of sodium thiosulfate, Na2S2O3. How could you determine whether the solution is unsaturated, saturated, or supersaturated? 17. Supersaturated solutions of most solids in water are prepared by cooling saturated solutions. Supersaturated solutions of most gases in water are prepared by heating saturated solutions. Explain the reasons for the difference in the two procedures. Suggest an explanation for the observations that ethanol, C2H5OH, is completely miscible with water and that ethanethiol, C2H5SH, is soluble only to the extent of 1.5 g per 100 mL of water. Calculate the percent by mass of KBr in a saturated solution of KBr in water at 10 C. See Figure 11.17 for useful data, and report the computed percentage to one significant digit. Which of the following gases is expected to be most soluble in water? Explain your reasoning. (a) CH4 (b) CCl4. Q: Supersaturated solutions of most solids in water are prepared by cooling what? Choices: - mineral solutions - dense solutions - plasma solutions - saturated solutions A:
A: saturated solutions
Question: Answer the following question given this paragraph: Q: Flow of what can introduce alleles that are advantageous or ones that are disadvantageous? Choices: - babies - eggs - larvae - genes A:
Answer: genes
*Question*
Answer the following question given this paragraph: Your own body cells burn fuel in combustion reactions. The fuel is glucose (C 6 H 12 O 6 ), a simple sugar. The process in which combustion of glucose occurs in body cells is called cellular respiration. This combustion reaction provides energy for life processes. Cellular respiration can be summed up by the equation:. Q: Cellular respiration in humans involves the combustion of what simple sugar? Choices: - starch - glutamate - insulin - glucose A:
**Answer**
glucose
(Q).
Answer the following question given this paragraph: It was not until the era of the ancient Greeks that we have any record of how people tried to explain the chemical changes they observed and used. At that time, natural objects were thought to consist of only four basic elements: earth, air, fire, and water. Then, in the fourth century BC, two Greek philosophers, Democritus and Leucippus, suggested that matter was not infinitely divisible into smaller particles but instead consisted of fundamental, indivisible particles called atoms. Unfortunately, these early philosophers did not have the technology to test their hypothesis. They would have been unlikely to do so in any case because the ancient Greeks did not conduct experiments or use the scientific method. They believed that the nature of the universe could be discovered by rational thought alone. Over the next two millennia, alchemists, who engaged in a form of chemistry and speculative philosophy during the Middle Ages and Renaissance, achieved many advances in chemistry. Their major goal was to convert certain elements into others by a process they called transmutation (Figure 1.13 "An Alchemist at Work"). In particular, alchemists wanted to find a way to transform cheaper metals into gold. Although most alchemists did not approach chemistry systematically and many appear to have been outright frauds, alchemists in China, the Arab kingdoms, and medieval Europe made major contributions, including the discovery of elements such as quicksilver (mercury) and the preparation of several strong acids. Q: It was not until the era of the ancient greeks that we have any record of how people tried to explain the chemical changes they observed and used. at that time, natural objects were thought to consist of only four basic elements: earth, air, fire, and this? Choices: - sky - soul - grass - water A:
(A).
water