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:
537.68 torr.
Explanation:
- We can use the general law of ideal gas:<em> PV = nRT.</em>
where, P is the pressure of the gas in atm.
V is the volume of the gas in L.
n is the no. of moles of the gas in mol.
R is the general gas constant,
T is the temperature of the gas in K.
- If n and V are constant, and have different values of P and T:
<em>(P₁T₂) = (P₂T₁).</em>
P₁ = 485 torr, T₁ = 40°C + 273 = 313 K,
P₂ = ??? torr, T₂ = 74°C + 273 = 347 K.
∴ P₂ = (P₁T₂)/(P₁) = (485 torr)(347 K)/(313 K) = 537.68 torr.
Answer:
(1) atomic numbers
Explanation:
The observed regularities in the properties of the elements on the periodic table are periodic functions of their atomic numbers.
- Atomic number is the number of protons in an atom.
- The periodic law states that "the properties of elements are a periodic function of their atomic number".
- Elements on the periodic table are arranged based on the atomic numbers they contain.
- The number of positively charged particles in an atom is the atomic number.
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive. Three of the most common types of decay are alpha decay (-decay), beta decay (-decay), and gamma decay (-decay), all of which involve emitting one or more particles or photons. The weak force is the mechanism that is responsible for beta decay, while the other two are governed by the usual electromagnetic and strong forces.[1]
Answer:
the net force us 0.............
Explanation:
please mark brain
