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
#SPJ1
Answer:
See explanation
Explanation:
The slope of a graph in which mass was plotted against volume is the density of the object. Density of objects have been measured and recorded in standard handbooks for the purpose of reference. If the density of an unknown substance is measured, it can now be compared with the density of known substances recorded in standard handbooks such as the handbook of physics and chemistry. By so doing, the unknown substance can be identified.
According to standard handbooks, the density of copper is 8.96 g/ml while that of nickel is 8.908 g/ml. If the average slope obtained is around 8.96 g/ml, then the metal is copper and not nickel.
An alternative to this method is to measure the refractive index of the piece of metal and compare the average values observed with the contents of standard handbooks in order to identify the unknown metal.
The coefficients needed to balance the equation would be 2, 7, 4, and 6 respectively.
<h3>Balancing chemical equation</h3>
This requires that the number of atoms of each element is the same both on the reactant and product's sides.
Hence, the balanced equation of the reaction becomes:
Thus, the coefficient for each species would be 2, 7, 4, and 6 respectively.
More on balancing chemical equations can be found here: brainly.com/question/15052184
#SPJ1
The equator will be least affected since it's orientation and distance to the sun changes the least from season to season.