Answer: As an object falls its potential energy decreases, while its kinetic energy increases. The decrease in potential energy is exactly equal to the increase in kinetic energy.
Explanation:
It takes 31 s for 1.27 M H₃PO₄ to decrease its concentration to 7.0% of its initial value following first-order kinetics.
<h3>What is first-order kinetics?</h3>
First-order kinetics occur when a constant proportion of a reactant disappears per unit time.
Let's consider the following first-order kinetics reaction with a rate constant k = 0.086 s⁻¹.
2 H₃PO₄(aq) = P₂O₅(aq) + 3 H₂O(aq)
Given the initial concentation is [H₃PO₄]₀ = 1.27 M, the concentration representing 7.0% of this value is:
[H₃PO₄] = 7.0% × 1.27 M = 0.089 M
We can calculate the time elapsed (t) using the following expression.
ln ([H₃PO₄]/[H₃PO₄]₀) = - k × t
ln (0.089 M/1.27 M) = - 0.086 s⁻¹ × t
t = 31 s
It takes 31 s for 1.27 M H₃PO₄ to decrease its concentration to 7.0% of its initial value following first-order kinetics.
Learn more about first-order kinetics here: brainly.com/question/18916637
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Answer:
The half-life of polonium-210 is approximately 138.792 days.
Explanation:
We must remember that the decay of a radioisotope is modelled by this ordinary differential equation:
Where:
- Current mass of the isotope, measured in grams.
- Time constant, measured in days.
Whose solution is:
Where 
is the initial mass of the isotope, measured in grams.
Our first step is to determine the value of the time constant:
If we know that 
and 
, then the time constant of the radioisotope is:
And lastly we find the half-life of polonium-210 (
), measured in days, by using this expression:
The half-life of polonium-210 is approximately 138.792 days.
<span>Soil
and water is a suspension because it consists of larger particles
suspended in the medium, which start to settle when allowed to stand.
Milk is a colloid because it consists of minute particles that remain
suspended in the medium. Hope I helped! Please mark as brainliest, to help me out. :)</span>
