The relative volumes of chloroform and water that should be used is 9:10
Concentration of solution in chloroform = 
( moles of chloroform )
Concentration of solution in water = 
( moles of water )
Dissociation constant at 
; 
Concentration of solution in chloroform / Concentration of solution in water
Meaning;
Since mole is present in chloroform and mole is present in water, Total mole of Caffeine present is 
Now, we substitute our given values into the equation
Therefore, the relative volumes of chloroform and water that should be used is 9:10
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Good electrical conductivity and electronegativities less than 1.7 are the properties and characteristic of Group 2 elements at STP.
<h3>What are the properties of group 2 elements?</h3>
Group 2 elements are metals so they are good conductors of heat and electricity. It has electronegativity values less than 1.7 and very reactive. They form 2+ charge in cationic form and also formed ionic bonds with other negatively charged elements.
So we can conclude that good electrical conductivity and electronegativities less than 1.7 are the properties and characteristic of Group 2 elements at STP.
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Answer:
Active transport
Explanation:
Sodium-potassium pumps are examples of Active type of cellular transport. Sodium potassium pump exchanges sodium ions from potassium ions through the plasma membrane of animal cells.
Whereas Active transport can be defined as movement of ions and molecules across a cell membrane to the region of higher concentration with the help of enzymes and energy.
This lesson is the first in a three-part series that addresses a concept that is central to the understanding of the water cycle—that water is able to take many forms but is still water. This series of lessons is designed to prepare students to understand that most substances may exist as solids, liquids, or gases depending on the temperature, pressure, and nature of that substance. This knowledge is critical to understanding that water in our world is constantly cycling as a solid, liquid, or gas.
In these lessons, students will observe, measure, and describe water as it changes state. It is important to note that students at this level "...should become familiar with the freezing of water and melting of ice (with no change in weight), the disappearance of wetness into the air, and the appearance of water on cold surfaces. Evaporation and condensation will mean nothing different from disappearance and appearance, perhaps for several years, until students begin to understand that the evaporated water is still present in the form of invisibly small molecules." (Benchmarks for Science Literacy<span>, </span>pp. 66-67.)
In this lesson, students explore how water can change from a solid to a liquid and then back again.
<span>In </span>Water 2: Disappearing Water, students will focus on the concept that water can go back and forth from one form to another and the amount of water will remain the same.
Water 3: Melting and Freezing<span> allows students to investigate what happens to the amount of different substances as they change from a solid to a liquid or a liquid to a solid.</span>
Answer:
see explanation...
Explanation:
Mg⁺²-24 Co⁺³-60 Clˉ-35
Protons (p⁺) 12 27 17
Neutrons (n⁰) 12 33 18
Electrons (eˉ) 10 24 18
(c) (b) (a)
12/2 : 12/2 : 10/2 27/3 : 33/3 : 24/3 #n⁰ = 18
6 : 6 : 5 9 : 11 : 8 #eˉ = 18
