Answer:
At 0.58 L of 0.540 M NaOH solution contain 12.5 g NaOH.
Explanation:
Given data:
At volume = ?
Mass of NaOH = 12.5 g
Molarity of solution = 0.540 M
Solution:
First of all we will calculate the number of moles of sodium hydroxide.
Number of moles = mass/molar mass
Number of moles = 12.5 g / 40 g/mol
Number of moles = 0.3125 mol
Volume of NaOH:
Molarity = number of moles / volume in L
Now we will put the values.
0.540 M = 0.3125 mol / volume in L
volume in L = 0.3125 mol / 0.540 mol/L
volume in L = 0.58 L
-390.3 KJ is the Hrxn for the reaction →
<h3>What is Hess's Law?</h3>
Hess's Law of Constant Heat Summation (or just Hess's Law) states that regardless of the multiple stages or steps of a reaction, the total enthalpy change for the reaction is the sum of all changes.
For Hess's Law, we need to get the corresponding equation below using the sequence of reactions given
By manipulating the reaction, either reversing them or multiplying/dividing them to a certain factor, we can get to the target equation as well as the total enthalpy.
→
→ ) ΔH = −74.6kJ (needs to reverse)
→ ΔH = −95.7kJ (retain)
→ ΔH = −184.6kJ (multiply by 2 to get and cancel out 4 HCl and )
Therefore, it is -390.3 KJ.
Hence, -390.3 KJ is the Hrxn for the reaction →
Learn more about the Hess's Law here:
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Answer:
The 3rd one is correct
Explanation:
Protons and neutrons have approximately the same mass, about 1.67 × 10−24 grams, which scientists define as one atomic mass unit (amu) or one Dalton. Each electron has a negative charge (−1) equal to the positive charge of a proton (+1). Neutrons are uncharged particles found within the nucleus.
The correct answer is fracture formation.
Fracture formation is not an indication of a chemical change.
Gas production, energy transfer are Precipitate information indications of a chemical change.
A chemical change is an irreversible process wherein there are rearrangements of the atoms in the molecules of a compound, resulting in the formation of a new compound with new chemical properties or composition.
A fracture is a fault line that divides rocks into two or more pieces. A fracture is a geological formation. Fracture is most often seen as crevice or deep fissures in rocks.