Answer:
1.0 *10^(-4) mol
Explanation:
For gases:
n1/n2 = V1/V2
n1/3.8*10^(-4) mol = 230 mL/ 860 mL
n1 = 3.8*10^(-4)*230/860 = 1.0 *10^(-4) mol
441 g CaCO₃ would have to be decomposed to produce 247 g of CaO
<h3>Further explanation</h3>
Reaction
Decomposition of CaCO₃
CaCO₃ ⇒ CaO + CO₂
mass CaO = 247 g
mol of CaO(MW=56 g/mol) :

From equation, mol ratio CaCO₃ : CaO = 1 : 1, so mol CaO :

mass CaCO₃(MW=100 g/mol) :

Answer:
H₂(g) + Cl₂(g) → 2HCl(g) + 185kJ
Explanation:
In a chemical reaction, enthalpy of reaction ΔH is a thermodynamic constant that gives information if the reaction is exothermic (Produce heat if reacts) or endothermic (Consume heat if reacts).
In the reaction:
H₂(g) + Cl₂(g) → 2HCl(g) ΔH = -185kJ
As ΔH <0, the reaction is exothermic, that means, <em>produce heat</em>, writing a balanced thermochemical equation:
<em>H₂(g) + Cl₂(g) → 2HCl(g) + 185kJ</em>
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The enthalpy is as a product beacause an exothermic reaction produces heat.
I hope it helps!
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