Answer:
5.56 × 10⁻⁸
Explanation:
Step 1: Given data
- Concentration of the weak acid (Ca): 0.187 M
Step 2: Calculate the concentration of H⁺
We will use the following expression.
pH = -log [H⁺]
[H⁺] = antilog -pH = antilog -3.99 = 1.02 × 10⁻⁴ M
Step 3: Calculate the acid dissociation constant (Ka)
We will use the following expression.
![Ka = \frac{[H^{+}]^{2} }{Ca} = \frac{(1.02 \times 10^{-4})^{2} }{0.187} = 5.56 \times 10^{-8}](https://tex.z-dn.net/?f=Ka%20%3D%20%5Cfrac%7B%5BH%5E%7B%2B%7D%5D%5E%7B2%7D%20%7D%7BCa%7D%20%3D%20%5Cfrac%7B%281.02%20%5Ctimes%2010%5E%7B-4%7D%29%5E%7B2%7D%20%7D%7B0.187%7D%20%3D%205.56%20%5Ctimes%2010%5E%7B-8%7D)
Answer:
Element with 6s subshell
Explanation:
Reactivity of an element depends on the electronic configuration and position of element in the periodic table as reactivity increases as we go down the periodic table.
This is so because number of shell increases as move down the periodic table and the last electron is further away from the nucleus.
Element with 6s subshell is the largest among 3s and 4s subshell and has more number of shells so it will react more than 3s and 4s subshell.
Hence, the correct answer is "Element with 6s subshell".
The actual yield is 43 g Cl₂.
The <em>limiting reactant was MnO₂</em> because it gave the smaller mass of Cl₂.
∴ The <em>theoretical yield</em> is 60.25 g Cl₂.
% yield = actual yield/theoretical yield × 100 %
Actual yield = theoretical yield × (% yield/100 %) = 60.25 g × (72 %/100%) = 43 g
Answer:
c) atomic number / alkaline earth metals/ and halogens
Explanation:
Elements of modern periodic table are arrang in atomic number; for its electron configuration and its chemical properties. This arrangement shows periodic trends.
Alkaline earth metals are a group of elements that are located in group 2 of the Periodic Table and are the following: Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba) and Radio (Ra).
The Halogens are the chemical elements that form group 17 (XVII A, previously used) or group VII A of the periodic table: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At) and teneso (Ts)
The rate constant of the second order reaction is 0.137 M-1s-1.
<h3>What is the rate constant?</h3>
For the second order reaction we can write;
1/[A] = kt + 1/[A]o
[A]o = initial concentration
[A] = final concentration
k = rate constant
t = time
Now;
1/0.319 = 13.5k + 1/ 0.740
1/0.319 - 1/0.740 = 13.5k
3.13 - 1.35 = 13k
k = 3.13 - 1.35/13
k = 0.137 M-1s-1
Learn more about second order reaction:brainly.com/question/12446045
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