Positively charged and the sodium ion would be a cation
Answer : The enthalpy of the reaction is, -2552 kJ/mole
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The given enthalpy of reaction is,

The intermediate balanced chemical reactions are:
(1)

(2)

(3)

(4)

Now we have to revere the reactions 1 and multiple by 2, revere the reactions 3, 4 and multiple by 2 and multiply the reaction 2 by 2 and then adding all the equations, we get :
(when we are reversing the reaction then the sign of the enthalpy change will be change.)
The expression for enthalpy of the reaction will be,



Therefore, the enthalpy of the reaction is, -2552 kJ/mole
The frequency : a) 7.5 x 10¹⁴ /s
<h3>Further explanation</h3>
Radiation energy is absorbed by photons
The energy in one photon can be formulated as

Where
h = Planck's constant (6,626.10⁻³⁴ Js)
f = Frequency of electromagnetic waves (/s or Hz)
f = c / λ
c = speed of light
= 3.10⁸ m/s
λ = wavelength
The wavelength(λ) of purple light is 400 x 10⁻⁹ m, so the frequency :

physical change because even though gas formation was observed, the water was undergoing a state change, which means that its original properties are preserved
Explanation:
The boiling of water is a physical change because the original properties of the water is preserved.
- A physical change is the one that alters the physical properties of matter.
- This kind of change is easily reversible as the water can be cooled back.
- No new kinds of matter is produced in this kind of change .
- The molecules of the matter still retains their property after.
During the boiling of water, intermolecular bonds called hydrogen bonds between the water molecules are broken. This makes the individual molecules free.
Learn more:
Hydrogen bonds brainly.com/question/10602513
#learnwithBrainly
Answer:
Density of concentrated H2SO4 = 1.99g/cm^3 = 1991.79Kg/m^3
Explanation:
mass of empty flask = 78.23g mass of flask filled when with water = 593.63g.
mass of flask filled when with concentrateds sulfuric acid, H2SO4 = 1026.57g
Mass of water = (mass of flask filled when with water) -
(mass of empty flask) = 593.63g - 78.23g = 515.4g
Volume of flask = volume of water = volume of concentrateds sulfuric acid, H2SO4 =
(mass of water)/ density of water) = 515.4g/1.00g/cm^3 = 515.4cm^3
The density of concentrated sulfuric acid is given by
Density of concentrated H2SO4 = (mass of H2SO4) ÷ (volume of H2SO4) = 1026.57g/515.4cm^3 = 1.99g/cm^3 = 1991.79Kg/m^3