Answer:
25.7 kJ/mol
Explanation:
There are two heats involved.
heat of solution of NH₄NO₃ + heat from water = 0
q₁ + q₂ = 0
n = moles of NH₄NO₃ = 8.00 g NH₄NO₃ × 1 mol NH₄NO₃/80.0 g NH₄NO₃
∴ n = 0.100 mol NH₄NO₃
q₁ = n * ΔHsoln = 0.100 mol * ΔHsoln
m = mass of solution = 1000.0 g + 8.00 g = 1008.0 g
q₂ = mcΔT = 58.0 g × 4.184 J°C⁻¹ g⁻¹ × ((20.39-21)°C) = -2570.19 J
q₁ + q₂ = 0.100 mol ×ΔHsoln – 2570.19 J = 0
ΔHsoln = +2570.19 J /0.100 mol = +25702 J/mol = +25.7 kJ/mol
1) Radioactive decay is the spontaneous decomposition of the unstable nucleus of an atom.
2) The emission of a particle or a photon.
For example, alpha decay is radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus).
3) The result is usually more stable element with smaller atomic number.
For example, in alpha decay atom transforms into an atom with an atomic number that is reduced by two and mass number that is reduced by four.
For example nuclear fission is radioactive decay process in which the nucleus of an atom splits into smaller parts and huge amount of energy is released.
<h3>A. an acidic............</h3>
Answer:
236 g/mol
Explanation:
This question is asking to calculate the molar mass/formula mass of calcium nitrate tetrahydrate with the chemical formula: Ca(NO3)2 · 4H20. This is done as follows:
Atomic mass of the constituent elements are as follows:
Ca = 40
N = 14
O = 16
H = 1
Hence, in Ca(NO3)2 · 4H20.
= 40 + {14 + 16(3)}2 + 4 {1(2) + 16}
= 40 + {14 + 48}2 + 4{2 + 16}
= 40 + {62}2 + 4{18}
= 40 + 124 + 72
= 236
Hence, the molar mass of Ca(NO3)2 · 4H20 is 236g/mol.
Explanation:
The periodic table brings order to information about the chemical elements. It helps chemists to understand why elements react as they do. Elements in the same group have similar chemical properties. This is because they have the same number of outer electrons and the same valency
