Answer:

Explanation:
Whenever a question asks you, "What is the concentration after a given time?" or something like that, you must use the appropriate integrated rate law expression.
The reaction is 2nd order, because the units of k are L·mol⁻¹s⁻¹.
The integrated rate law for a second-order reaction is
![\dfrac{1}{\text{[A]}} =\dfrac{1}{\text{[A]}_{0}}+ kt](https://tex.z-dn.net/?f=%5Cdfrac%7B1%7D%7B%5Ctext%7B%5BA%5D%7D%7D%20%3D%5Cdfrac%7B1%7D%7B%5Ctext%7B%5BA%5D%7D_%7B0%7D%7D%2B%20kt)
Data:
k = 2.4 × 10⁻²¹ L·mol⁻¹s⁻¹
[A]₀ = 0.0100 mol·L⁻¹
[A] = 0.009 00 mol·L⁻¹
Calculation
:
![\begin{array}{rcl}\dfrac{1}{\text{[A]}} & = & \dfrac{1}{\text{[A]}_{0}}+ kt\\\\\dfrac{1}{0.00900 }& = & \dfrac{1}{0.0100} + 2.4 \times 10^{-21} \, t\\\\111.1&=& 100.0 + 2.4 \times 10^{-21} \, t\\\\11.1& = & 2.4 \times 10^{-21} \, t\\t & = & \dfrac{11.1}{ 2.4 \times 10^{-21}}\\\\& = & \mathbf{4.6 \times 10^{21}}\textbf{ s}\\\end{array}\\\text{It will take $\large \boxed{\mathbf{4.6 \times 10^{21}}\textbf{ s}}$ for the HI to decompose}](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Brcl%7D%5Cdfrac%7B1%7D%7B%5Ctext%7B%5BA%5D%7D%7D%20%26%20%3D%20%26%20%5Cdfrac%7B1%7D%7B%5Ctext%7B%5BA%5D%7D_%7B0%7D%7D%2B%20kt%5C%5C%5C%5C%5Cdfrac%7B1%7D%7B0.00900%20%7D%26%20%3D%20%26%20%5Cdfrac%7B1%7D%7B0.0100%7D%20%2B%202.4%20%5Ctimes%2010%5E%7B-21%7D%20%5C%2C%20t%5C%5C%5C%5C111.1%26%3D%26%20100.0%20%2B%202.4%20%5Ctimes%2010%5E%7B-21%7D%20%5C%2C%20t%5C%5C%5C%5C11.1%26%20%3D%20%26%202.4%20%5Ctimes%2010%5E%7B-21%7D%20%5C%2C%20t%5C%5Ct%20%26%20%3D%20%26%20%5Cdfrac%7B11.1%7D%7B%202.4%20%5Ctimes%2010%5E%7B-21%7D%7D%5C%5C%5C%5C%26%20%3D%20%26%20%5Cmathbf%7B4.6%20%5Ctimes%2010%5E%7B21%7D%7D%5Ctextbf%7B%20s%7D%5C%5C%5Cend%7Barray%7D%5C%5C%5Ctext%7BIt%20will%20take%20%24%5Clarge%20%5Cboxed%7B%5Cmathbf%7B4.6%20%5Ctimes%2010%5E%7B21%7D%7D%5Ctextbf%7B%20s%7D%7D%24%20for%20the%20HI%20to%20decompose%7D)
It increases availability of food for humans
Answer: It showed that all atoms contain electrons.
Explanation:
- J.J. Thomson's experiments inside a cathode ray tube in the presence of an electric field showed that all atoms contain tiny negatively charged subatomic particles "electrons".
- Also, Thomson's plum pudding model of the atom had negatively-charged electrons embedded within a positively-charged "soup."
- Furthermore, Rutherford's gold foil experiment showed that the atom is mostly empty space with a tiny positively-charged nucleus.
- Then, Rutherford proposed the nuclear model of the atom based on these results.
We are given with the mass of pure iron that reacts with oxygen to form an oxide which has a given mass as well. the mass of oxygen reacted is 8.15-6.25 g or 1.9 grams. THen we convert the mass of the reactants to moles. Iron is equal to 0.1119 moles and oxygen is equal to 0.1188. We divide each number to the less amount. Hence iron is 1 and oxygen is approx 1. The empirical formula hence is FeO or ferrous oxide or Iron (II) oxide.