Answer:
Based on the Modern Periodic table, there is an increase in the electropositivity of the atom down the group as well as increases across a period. On comparing the electropositivities of the mentioned oxides central atom, it is seen that Ca is most electropositive followed by Al, Si, C, P, and S is the least electropositive.
With the decrease in the electropositivity, there is an increase in the acidity of the oxides. Thus, the increasing order of the oxides from the least acidic to the most acidic is:
CaO > Al2O3 > SiO2 > CO2 > P2O5 > SO3. Hence, CaO is the least acidic and SO3 is the most acidic.
First, we must know what happens in the precipitation reaction. This type of reaction is a double replacement reactions. It is consists of two reactant compounds which interchange cations and anions to form two products. One of the products is an insoluble solid called a precipitate. For the precipitation of CaCO₃, there are two consecutive reactions involved:
1. Slaking of quicklime, CaO
CaO + H₂O ⇒ Ca(OH)₂
2. Precipitation
Ca(OH)₂ + CO₂ ⇒ CaCO₃ + H₂O
The ions that make up the H₂O molecule are H⁺ and OH⁻. According to solubility rules, the cation (positively charged ion) is likely to be attracted to an anion (negatively charged ion). Together, they form an ionic bond. This type of bond is when there is a complete transfer of electrons between the two. The Ca²⁺ cation lacks 2 electrons, while the anion OH⁻ has an excess 1 electron. In order to be stable, 1 Ca²⁺ ion and 2 OH⁻ ions must combine.
Therefore, the answer is OH⁻ ion.
Answer:
I don't know chemistry
Explanation:
because this is the hardest subject in the world nobody can solve it so do yourself ok Beta
Answer:
Part a: <em>Units of k is </em>
<em> where reaction is first order in A and second order in B</em>
Part b: <em>Units of k is </em>
<em> where reaction is first order in A and second order overall.</em>
Part c: <em>Units of k is </em>
<em> where reaction is independent of the concentration of A and second order overall.</em>
Part d: <em>Units of k is </em>
<em> where reaction reaction is second order in both A and B.</em>
Explanation:
As the reaction is given as

where as the rate is given as
![r=k[A]^x[B]^y](https://tex.z-dn.net/?f=r%3Dk%5BA%5D%5Ex%5BB%5D%5Ey)
where x is the order wrt A and y is the order wrt B.
Part a:
x=1 and y=2 now the reaction rate equation is given as
![r=k[A]^1[B]^2](https://tex.z-dn.net/?f=r%3Dk%5BA%5D%5E1%5BB%5D%5E2)
Now the units are given as
![r=k[A]^1[B]^2\\M/s =k[M]^1[M]^2\\M/s =k[M]^{1+2}\\M/s =k[M]^{3}\\M^{1-3}/s =k\\M^{-2}s^{-1} =k](https://tex.z-dn.net/?f=r%3Dk%5BA%5D%5E1%5BB%5D%5E2%5C%5CM%2Fs%20%3Dk%5BM%5D%5E1%5BM%5D%5E2%5C%5CM%2Fs%20%3Dk%5BM%5D%5E%7B1%2B2%7D%5C%5CM%2Fs%20%3Dk%5BM%5D%5E%7B3%7D%5C%5CM%5E%7B1-3%7D%2Fs%20%3Dk%5C%5CM%5E%7B-2%7Ds%5E%7B-1%7D%20%3Dk)
The units of k is 
Part b:
x=1 and o=2
x+y=o
1+y=2
y=2-1
y=1
Now the reaction rate equation is given as
![r=k[A]^1[B]^1](https://tex.z-dn.net/?f=r%3Dk%5BA%5D%5E1%5BB%5D%5E1)
Now the units are given as
![r=k[A]^1[B]^1\\M/s =k[M]^1[M]^1\\M/s =k[M]^{1+1}\\M/s =k[M]^{2}\\M^{1-2}/s =k\\M^{-1}s^{-1} =k](https://tex.z-dn.net/?f=r%3Dk%5BA%5D%5E1%5BB%5D%5E1%5C%5CM%2Fs%20%3Dk%5BM%5D%5E1%5BM%5D%5E1%5C%5CM%2Fs%20%3Dk%5BM%5D%5E%7B1%2B1%7D%5C%5CM%2Fs%20%3Dk%5BM%5D%5E%7B2%7D%5C%5CM%5E%7B1-2%7D%2Fs%20%3Dk%5C%5CM%5E%7B-1%7Ds%5E%7B-1%7D%20%3Dk)
The units of k is 
Part c:
x=0 and o=2
x+y=o
0+y=2
y=2
y=2
Now the reaction rate equation is given as
![r=k[A]^0[B]^2](https://tex.z-dn.net/?f=r%3Dk%5BA%5D%5E0%5BB%5D%5E2)
Now the units are given as
![r=k[B]^2\\M/s =k[M]^2\\M/s =k[M]^{2}\\M^{1-2}/s =k\\M^{-1}s^{-1} =k](https://tex.z-dn.net/?f=r%3Dk%5BB%5D%5E2%5C%5CM%2Fs%20%3Dk%5BM%5D%5E2%5C%5CM%2Fs%20%3Dk%5BM%5D%5E%7B2%7D%5C%5CM%5E%7B1-2%7D%2Fs%20%3Dk%5C%5CM%5E%7B-1%7Ds%5E%7B-1%7D%20%3Dk)
The units of k is 
Part d:
x=2 and y=2
Now the reaction rate equation is given as
![r=k[A]^2[B]^2](https://tex.z-dn.net/?f=r%3Dk%5BA%5D%5E2%5BB%5D%5E2)
Now the units are given as
![r=k[A]^2[B]^2\\M/s =k[M]^2[M]^2\\M/s =k[M]^{2+2}\\M/s =k[M]^{4}\\M^{1-4}/s =k\\M^{-3}s^{-1} =k](https://tex.z-dn.net/?f=r%3Dk%5BA%5D%5E2%5BB%5D%5E2%5C%5CM%2Fs%20%3Dk%5BM%5D%5E2%5BM%5D%5E2%5C%5CM%2Fs%20%3Dk%5BM%5D%5E%7B2%2B2%7D%5C%5CM%2Fs%20%3Dk%5BM%5D%5E%7B4%7D%5C%5CM%5E%7B1-4%7D%2Fs%20%3Dk%5C%5CM%5E%7B-3%7Ds%5E%7B-1%7D%20%3Dk)
The units of k is 