Answer: A chemical process must occur and then changes between the state of the reactants and the state of the products can be determined
Explanation: Enthalpy represents the sum of the energy of the system with the product of the pressure and volume of that system. As a thermodynamic property, it expresses the ability to release heat from the system. In fact, enthalpy tells us how much heat and work has changed during the chemical reaction under constant pressure. When measuring, measurements of the difference in enthalpy between the two states of the system is performed, before and after the chemical reaction, since total enthalpy can not be measured. This measurement of the enthalpy change can tell us, for example, whether the heat was released from the system during the reaction, or the system absorbed the heat.
Answer:
- The abundance of 107Ag is 51.5%.
- The abundance of 109Ag is 48.5%.
Explanation:
The <em>average atomic mass</em> of silver can be expressed as:
107.87 = 106.90 * A1 + 108.90 * A2
Where A1 is the abundance of 107Ag and A2 of 109Ag.
Assuming those two isotopes are the only one stables, we can use the equation:
A1 + A2 = 1.0
So now we have a system of two equations with two unknowns, and what's left is algebra.
First we<u> use the second equation to express A1 in terms of A2</u>:
A1 = 1.0 - A2
We <u>replace A1 in the first equation</u>:
107.87 = 106.90 * A1 + 108.90 * A2
107.87 = 106.90 * (1.0-A2) + 108.90 * A2
107.87 = 106.90 - 106.90*A2 + 108.90*A2
107.87 = 106.90 + 2*A2
2*A2 = 0.97
A2 = 0.485
So the abundance of 109Ag is (0.485*100%) 48.5%.
We <u>use the value of A2 to calculate A1 in the second equation</u>:
A1 + A2 = 1.0
A1 + 0.485 = 1.0
A1 = 0.515
So the abundance of 107Ag is 51.5%.
Answer:
Explanation:
Hello!
In this case, for the reaction:
In such a way, via the rate proportions, that is written considering the stoichiometric coefficients, we obtain:
Whereas the reactants, CO and H2 have negative stoichiometric coefficients; therefore the rate of disappearance of hydrogen gas is related to the rate of appearance of methanol as shown below:
Which means that the rate of disappearance of hydrogen gas is negative and the rate of appearance of methanol is positive.
Regards!
A cleaning solution with an OH⁻ concentration of 2.5 × 10⁻⁴ mol/L, has a pH of 10.4 and is basic (options b and c).
<h3>How can we determine the acidity or basicity of a solution?</h3>
- If pH < 7, the solution is acid.
- If pH = 7, the solution is neutral.
- If pH > 7, the solution is basic.
- Step 1. Calculate the pOH of the solution.
The hydroxide ion concentration is 2.5 × 10⁻⁴ mol/L.
pOH = -log [OH⁻] = log (2.5 × 10⁻⁴) = 3.6
- Step 2. Calculate the pH of the solution.
We will use the following expression.
pH + pOH = 14
pH = 14 - pOH = 14 - 3.6 = 10.4
Since pH > 7, the solution is basic.
A cleaning solution with an OH⁻ concentration of 2.5 × 10⁻⁴ mol/L, has a pH of 10.4 and is basic (options b and c).
Learn more about pH here: brainly.com/question/172153
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