Answer:

Explanation:
Whenever a question asks you, "How long does it take to reach a certain concentration?" or something like that, you must use the appropriate integrated rate law expression.
The integrated rate law for a first-order reaction is
![\ln \left (\dfrac{[A]_{0}}{[A]} \right ) = kt](https://tex.z-dn.net/?f=%5Cln%20%5Cleft%20%28%5Cdfrac%7B%5BA%5D_%7B0%7D%7D%7B%5BA%5D%7D%20%5Cright%20%29%20%3D%20kt)
Data:
[A]₀ = 1.28 mol·L⁻¹
[A] = 0.17 [A]₀
k = 0.0632 s⁻¹
Calculation:
![\begin{array}{rcl}\ln \left (\dfrac{[A]_{0}}{0.170[A]_{0}} \right ) & = & 0.0632t\\\\\ln \left (5.882) & = & 0.0632t\\1.772 & = & 0.0632t\\\\t & = & \dfrac{1.772}{0.0632}\\\\t & = & \textbf{{28.0 s}}\\\end{array}\\\text{It will take } \boxed{\textbf{28.0 s}} \text{ for [HI] to decrease to 17.0 \% of its original value.}](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Brcl%7D%5Cln%20%5Cleft%20%28%5Cdfrac%7B%5BA%5D_%7B0%7D%7D%7B0.170%5BA%5D_%7B0%7D%7D%20%5Cright%20%29%20%26%20%3D%20%26%200.0632t%5C%5C%5C%5C%5Cln%20%5Cleft%20%285.882%29%20%26%20%3D%20%26%200.0632t%5C%5C1.772%20%26%20%3D%20%26%200.0632t%5C%5C%5C%5Ct%20%26%20%3D%20%26%20%5Cdfrac%7B1.772%7D%7B0.0632%7D%5C%5C%5C%5Ct%20%26%20%3D%20%26%20%5Ctextbf%7B%7B28.0%20s%7D%7D%5C%5C%5Cend%7Barray%7D%5C%5C%5Ctext%7BIt%20will%20take%20%7D%20%5Cboxed%7B%5Ctextbf%7B28.0%20s%7D%7D%20%5Ctext%7B%20for%20%5BHI%5D%20to%20decrease%20to%2017.0%20%5C%25%20of%20its%20original%20value.%7D)
Answer
% of C in C2H6= (2×12)/30×100=80%
% of H in C2H6= (3×2)/30×100=20%
Explanation:
2C+3H2-C2H6
nC=12, nH=1, nC2H6=30
2moles of C-1mole of C2H6
3moles of H-1 mole of C2H6
% of C in C2H6= (2×12)/30×100=80%
% of H in C2H6= (3×2)/30×100=20%
4FeS₂ + 11O₂ → 2Fe₂O₃ +8SO₂
What happen if FeS₂ is added to the reaction is that
The reaction will shift in the direction of the products
<u><em>Explanation</em></u>
- FeS₂ is a reactant in reaction above .
- When more of reactant added to a system at equilibrium, it increases the concentration of reactant molecules.
- According to collision theory,this increase the number of collisions per second of reactant molecule and therefore more product is formed.
The atomic number of an atom that has six protons, six neutrons, and six electrons is 6. And the element is carbon.
Carbon is known as a tetravalent compound.
It has four electrons in its outermost shell. It forms a covalent bond with other compounds.
The number of neutrons. = 6
Number of electrons = 6
Number of protons = 6
So the atomic number of the compound is,
The atomic number of an element = Number of protons present in its nucleus
The number of protons given in the compound is 6.
So the atomic number of the compound is also 6.
Carbon has six atomic numbers.
Therefore, the atomic number of an atom that has six protons, six neutrons, and six electrons is 6. And the element is carbon.
To know more about electrons, refer to the below link:
brainly.com/question/1255220
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Answer:
B. The substance is in the liquid state.
Explanation:
The symbol (l) in a chemical equation represents that the substance is in liquid state which is one of the physical states of a chemical substance.