Answer:
It’s true
Explanation:
If we account for all reactants and products in a chemical reaction, the total mass will be the same at any point in time in any closed system. ... The Law of Conservation of Mass holds true because naturally occurring elements are very stable at the conditions found on the surface of the Earth.
The balanced chemical reaction for the described reaction above is,
Na2CO3 + 2HCl ---> 2NaCl + H2CO3
From the reaction, 1 mole of Na2CO3 is needed to produce 2 moles of NaCl. In terms of mass, 106 grams of Na2CO3 are needed to produce 116.9 grams of NaCl. From this,
(23.4 g NaCl) x (106 g Na2CO3 / 116.9 NaCl = 21.22 g Na2CO3
Thus, approximately 21.22 g Na2CO3 is needed for the desired reaction.
Answer:
The answer to your question is ΔH° rxn = -1343.9 kJ/mol
Explanation:
P₄O₆ (s) + 2 O₂ (g) ⇒ P₄O₁₀
ΔH°rxn = ?
Formula
ΔH°rxn = ∑H° products - ∑H° reactants
H° P₄O₆ = -1640.1 kJ/mol
H° O₂ = 0 kJ/mol
H° P₄O₁₀ = -2984 kJ/mol
-Substitution
ΔH° rxn = (-2984) - (-1640.1) - (0)
-Simplification
ΔH° rxn = -2984 + 1640.1
ΔH° rxn = -1343.9 kJ/mol
