Answer is: -601,2 kJ/mol
Chemical reaction: Mg(OH)₂ → MgO + H₂O.
ΔHrxn = 37,5 kJ/mol.
ΔHf(Mg(OH)₂) = <span>−924,5 kJ/mol.
</span>ΔHf(H₂O) = <span>−285,8 kJ/mol.
</span>ΔHrxn -enthalpy of reaction.
ΔHf - enthalpy of formation.
<span>ΔHrxn=∑productsΔHf−∑reactantsΔHf.
</span>ΔHf(MgO) = -924,5 kJ/mol - (-285,8 kJ/mol) + 37,5 kj/mol.
ΔHf(MgO) = -601,2 kJ/mol.
Answer:
what are the roles of minerals in maintaning homeostasis?
30ml of a 2.50 M hydrochloric acid solution is required to make 100.0 mL of a 0.750 M solution.
<h3>What is HCl?</h3>
HCl is an acid which is made up of hydrogen and chlorine gas.
By the formula of dilution
M1V1 = M2V2
where V1 = 2.50 m
M2 = 100.0
V2 = 0.750 m
M1 × 2.50 m = 100.0 × 0.750 m
M1 = 30 ml
Thus, the M1 is 30 ml option a is correct.
Learn more about HCl
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Answer:
51.53 grams .
Explanation:
Na₃PO₄ ⇄ 3Na⁺¹ + PO₄⁻³ .
1 mole 3 mole
725 mL of 1.3 M Na⁺ ions
= .725 x 1.3 moles of Na⁺ ions
= .9425 moles
3 mole of Na⁺ is formed by 1 mole of Na₃PO₄
.9425 mole of Na⁺ is formed by .9425/3 mole of Na₃PO₄
Na₃PO₄ needed = .9425/3 moles = .3142 moles
Molecular weight of Na₃PO₄ = 164
grams of Na₃PO₄ needed = .3142 x 164 = 51.53 grams .
