True but no one know Exactly how many stars there are
The heat of solution is -51.8 kJ/mol
<h3>What is the heat of solution?</h3>
We know that in a calorimeter, there is no loss or gain of energy. It is a good example of a closed system.
Number of moles of KOH = 11.9-g/56 g/mol = 0.21 moles
Temperature rise = 26.0 ∘c
Mass of the water = 100.0 grams
Heat capacity = 4.184 j/g⋅°c
Then;
ΔH = mcθ
ΔH = 100g * 4.184 j/g⋅°c * 26.0 ∘c = 10.88 kJ
Heat of solution = -(10.88 kJ/ 0.21 moles) = -51.8 kJ/mol
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The atomic mass of the magnesium is : 24.31⋅g.
<h3>What is isotopes?</h3>
Isotopes are members of a family of elements that all have the same number of protons and different numbers of neutrons. The number of protons in the nucleus determines the atomic number of an element on the periodic table.
Magnesium has three natural isotopes: ²⁴Mg, ²⁵Mg, and ²⁶Mg.
<h3>What is atomic mass ?</h3>
Atomic mass is the mass of an atom. The SI unit of mass is the kilogram, while atomic mass is often expressed in the non-SI unit dalton (synonymous with uniform atomic mass unit). 1 Da is defined as 1/12 the mass of a free carbon-12 atom at rest in the ground state.
Calculation :
The atomic mass is the weighted average of the individual isotopic masses:
(23.99×78.99%+24.99×10.00%+25.98×11.01%)⋅g=24.31⋅g
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The second one, I could be mistaken though
I am sorry can you explain it more?
