Answer:
ΔH°r = -483.64 kJ
Explanation:
Let's consider the following balanced equation.
2 H₂(g) + O₂(g) ⇒ 2 H₂O(g)
We can calculate the standard enthalpy change of the reaction (ΔH°r) using the following expression.
ΔH°r = ∑ΔH°f(p) × np - ∑ΔH°f(r) × nr
where
ΔH°f: standard heat of formation
n: moles
p: products
r: reactants
ΔH°r = ΔH°f(H₂O(g)) × 2 mol - ΔH°f(H₂(g)) × 2 mol - ΔH°f(O₂(g)) × 1 mol
ΔH°r = (-241.82 kJ/mol) × 2 mol - 0 kJ/mol × 2 mol - 0 kJ/mol × 1 mol
ΔH°r = -483.64 kJ
Answer:
a process that involves rearrangement of the molecular or ionic structure of a substance as distinct from a change in physical form or a nuclear reaction
Explanation:
please mark brainlest
Answer:
The correct option is;
A) The water molecules group together in clumps.
Explanation:
To answer the question, we look at each option as follows
A) The water molecules group together in clumps
This does not aid dissolution of compounds as clumping excludes non polar molecules, making them less soluble.
B) The partial negative oxygen atom end of the water molecule surround cations.
When an ionic compound such as NaCl is dissolved in water, the oxygen atoms surround the positive Na⁺ cations in the solution.
C) The partial positive hydrogen atom end of the water molecule surround anions
When the ionic NaCl compound is dissolved in water, the hydrogen atoms surround the negative Cl⁻ anions in the solution.
D) The water molecules also dissolve nonelectrolytes by creating a hydration sphere around the molecule.
Water is able to dissolve nonelectrolytes by creating an hydration sphere or hydration shell around the molecule.
There are approximately 160 grams in 1 mol of Fe2O3 molecules. Therefore, there would be 79/160= 0.49375 mols of Fe2O3 molecules in 79 grams. There are 5 atoms in total for each molecule of Fe2O3, therefore 79/160 * 5 = 79/32 = 2.46875 mols of atoms.
