She must have used the torch as Sun, the tennis ball as Earth and the marble as Moon.
Answer:
Well we know that matter is neither created nor destroyed by chemical reactions or physical transformations. It is not destroyed it simply was converted to gas. =D
<u>Given:</u>
H2(g) + Cl2 (g) → 2HCl (g)
<u>To determine:</u>
The enthalpy of the reaction and whether it is endo or exothermic
<u>Explanation:</u>
Enthalpy of a reaction is given by the difference between the enthalpy of formation of reactants and products
ΔH = ∑nHf (products) - ∑nHf (reactants)
= [2Hf(HCl)] - [Hf(H2) + Hf(Cl2)] = 2 (-92.3) kJ = - 184.6 kJ
Since the reaction enthalpy is negative, the reaction is exothermic
<u>Ans:</u> The enthalpy of reaction is -184. kJ and the reaction is exothermic
The options are labelled as:
1 2
3 4
5 6
7 8
Protons: 1, 5, 7
Neutrons: 2, 8
Electron: 3, 4, 6
