What does Hess's law state can be done in order to be able to react solid magnesium with oxygen gas safely (that is, without exp
1 answer:
Answer:
C. The reaction can be broken down and performed in steps
Explanation:
Hess's Law of Constant Heat Summation states that irrespective of the number of steps followed in a reaction, the total enthalpy change for the reaction is the sum of all enthalpy changes corresponding to all the steps in the overall reaction. The implication of this law is that the change of enthalpy in a chemical reaction is independent of the pathway between the initial and final states of the system.
To obtain MgO safely without exposing magnesium to flame, the reaction sequence shown in the image attached may be carried out. Since the enthalpy of the overall reaction is independent of the pathway between the initial and final states of the system, the sum of the enthalpy of each step yields the enthalpy of formation of MgO.
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Answer:- Mole ratio of D to A is 4:3.
Explanations:- Mole ratio for a chemical reaction is the ratio of the coefficients.
The given generic chemical reaction is:
The numbers written in front of each chemical species in the chemical reaction are their moles. For the given generic chemical reaction the coefficient of A is 3 and that of B is 1. So, the mole ratio of A to B is 3:1.
Similarly if we want to write the mole ratio of C to D then it is 1:4.
We are asked to write the mole ratio of D to A. So, like the other ratios, the mole ratio of D to A is 4:3 as the coefficient of D is 4 and A is 3.
Explanation:
Given parameters:
Wavelength of photon = 827nm = 827 x 10⁻⁹m
Unknown:
Energy of the photon = ?
Type of radiation = ?
Solution:
The energy of a photon can be derived using the expression below:
E =
h is the Planck's constant = 6.63 x 10⁻³⁴m²kg/s
c is the speed of light = 3 x 10⁸m/s
Insert the parameters and solve;
E =
E = 2.4 x 10⁻¹⁹J
Type of radiation:
Near infrared radiation