Answer:
A. K₂C₂O₄ Potassium oxalate
B. CuC₂O₄ Copper oxalate
C. Bi₂(C₂O₄)₃ Bismuth (III) oxalate
D. Pb(C₂O₄)₂ Lead (IV) oxalate
E. (NH₄)₂C₂O₄ Ammonium oxalate
F. HC₂O₄⁻ Acid oxalate
Explanation:
C₂O₄⁻² → oxalate anion
This is the conjugate base from the H₂C₂O₄ which is the oxalic acid. A weak dyprotic acid that can release 2 protons.
A. 2K⁺ + C₂O₄⁻² → K₂C₂O₄ Potassium oxalate
It can be formed by the neutralization of the acid with the base
H₂C₂O₄ + 2KOH → K₂C₂O₄ + 2H₂O
B. Cu²⁺ + C₂O₄⁻² ⇄ CuC₂O₄ ↓
This is a precipitate.
C. 2Bi³⁺ + 3C₂O₄⁻² ⇄ Bi₂(C₂O₄)₃ ↓
This is a precipitate.
D. Pb⁴⁺ + 2C₂O₄⁻² ⇄ Pb(C₂O₄)₂ ↓
This is a precipitate.
E. 2NH₄⁺ + C₂O₄⁻² ⇄ (NH₄)₂C₂O₄ ↓
This is a precipitate.
F. This is the conjugate strong base, for the weak acid
H⁺ + C₂O₄⁻² ⇄ HC₂O₄⁻
HC₂O₄⁻ + H₂O ⇄ C₂O₄⁻² + H₃O⁺ Ka
HC₂O₄⁻ + H₂O ⇄ H₂C₂O₄ + OH⁻ Kb
HC₂O₄⁻ is an amphoteric compound
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:
Because both CaCl2 and CaBr2 both contain elements (Chlorine and Bromine) from the same group (group 7)
Explanation:
Elements are placed into different groups in the periodic table. Elements in the same group are those that have the same number of valence electrons in their outermost shell and as a result will behave similar chemically i.e. will react with other elements in the same manner.
Chlorine and Bromine are two elements belonging to group 7 of the periodic table. They are called HALOGENS and they have seven valence electrons in their outermost shell. Hence, when they form a compound with Calcium, a group two element, these compounds (CaCl2 and CaBr2) will possess similar properties because they have elements that are from the same group (halogen group).
Answer : The concentration of NOBr after 95 s is, 0.013 M
Explanation :
The integrated rate law equation for second order reaction follows:
![k=\frac{1}{t}\left (\frac{1}{[A]}-\frac{1}{[A]_o}\right)](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B1%7D%7Bt%7D%5Cleft%20%28%5Cfrac%7B1%7D%7B%5BA%5D%7D-%5Cfrac%7B1%7D%7B%5BA%5D_o%7D%5Cright%29)
where,
k = rate constant = 
t = time taken = 95 s
[A] = concentration of substance after time 't' = ?
![[A]_o](https://tex.z-dn.net/?f=%5BA%5D_o)
= Initial concentration = 0.86 M
Now put all the given values in above equation, we get:
![0.80=\frac{1}{95}\left (\frac{1}{[A]}-\frac{1}{(0.86)}\right)](https://tex.z-dn.net/?f=0.80%3D%5Cfrac%7B1%7D%7B95%7D%5Cleft%20%28%5Cfrac%7B1%7D%7B%5BA%5D%7D-%5Cfrac%7B1%7D%7B%280.86%29%7D%5Cright%29)
[A] = 0.013 M
Hence, the concentration of NOBr after 95 s is, 0.013 M
-Positively charged nucleus
-Empty spaced
-Dense core
