Answer:
1.135 M.
Explanation:
- For the reaction: <em>2HI → H₂ + I₂,</em>
The reaction is a second order reaction of HI,so the rate law of the reaction is: Rate = k[HI]².
- To solve this problem, we can use the integral law of second-order reactions:
<em>1/[A] = kt + 1/[A₀],</em>
where, k is the reate constant of the reaction (k = 1.57 x 10⁻⁵ M⁻¹s⁻¹),
t is the time of the reaction (t = 8 hours x 60 x 60 = 28800 s),
[A₀] is the initial concentration of HI ([A₀] = ?? M).
[A] is the remaining concentration of HI after hours ([A₀] = 0.75 M).
∵ 1/[A] = kt + 1/[A₀],
∴ 1/[A₀] = 1/[A] - kt
∴ 1/[A₀] = [1/(0.75 M)] - (1.57 x 10⁻⁵ M⁻¹s⁻¹)(28800 s) = 1.333 M⁻¹ - 0.4522 M⁻¹ = 0.8808 M⁻¹.
∴ [A₀] = 1/(0.0.8808 M⁻¹) = 1.135 M.
<em>So, the concentration of HI 8 hours earlier = 1.135 M.</em>
Answer:
1)
2) The dependent variable = The time it takes for one pendulum swing
3) The independent variable = The length of the pendulum string with weight at the bottom
Explanation:
The relationship between the length of the pendulum string and the time it takes for one pendulum swing is giving as follows;

Where;
T = The period of oscillation = The time to complete one oscillation =Two swings of the pendulum
L = The length of the pendulum
g = The acceleration due to gravity
Therefore, the time it takes for one pendulum swing is directly proportional to the square root of the length of the pendulum
The dependent variable = The time it takes for one pendulum swing
Th independent variable = The length of the pendulum string with weight at the bottom.
Microbes are so small that they are able to "hide" in the cracks and crevices in your hand even with the help of sanitizer it only kills 99% not 100% so font dump that soap yet because you'll be wanting to kill that 1% that is causing you disease and fermintation
Answer-kinetic energy. The human experience of sound is caused by vibrations. The object creating the sound creates waves of movement through a medium, like air, until it reaches our eardrums, which then vibrate and our brain interprets that as sound. Here are some examples of sound energy:
Answer:
carbon-14
Explanation:
becouse protons and neutrons are nagetivly charged