For this type of problem, it is essential for you to have a data on the standard heats of formation of the substances given. For elemental substances or diatomic gases, the standard heat of formation is 0. Standard means the temperature is at 0°C and pressure at 1 atm. Calculate the standard heat of reaction using:
ΔH°rxn = ∑(Stoichiometric coefficient×ΔHf of products) - ∑(Stoichiometric coefficient×ΔHf of reactants)
Then, use this equation to find the reaction at T = 500°C and P = 1 bar:
ΔHrxn = ΔH°rxn + [∑(Stoichiometric coefficient×Cp of products) - ∑(Stoichiometric coefficient×ΔHf of reactants)]ΔT
So, you also need the Cp or specific heat capacities of the substances.
To find the number of moles of gas we can use the ideal gas law equation, we dont need to use the mass of gas given as we only have to find the number of moles
PV = nRT
P - pressure - 300.0 kPa
V - volume - 25.0 x 10⁻³ m³
n - number of moles
R - universal gas constant - 8.314 Jmol⁻¹K⁻¹
T - temperature in Kelvin - 27 °C + 273 = 300 K
substituting these values in the equation
300.0 kPa x 25.0 x 10⁻³ m³ = n x 8.314 Jmol⁻¹K⁻¹ x 300 K
n = 3.01 mol
number of mols of gas - 3.01 mol
Answer:
The molarity of the acid HX is 6.0 M.
Explanation:
We determine the amount of moles of KOH used to neutralize the acid:
=0.12 moles KOH
Then, we calculate the amount of moles of acid:
0.12 moles KOH×
=0.12 moles HX
The molarity of HX is:
=6.0 M
Answer:
D. The atoms are arranged with alternating positive and negative charges. When struck, the lattice shifts putting positives against positives and negatives against negatives.
Explanation:
Metallic crystals takes their properties as a result of metallic bonds in between the atoms.
Metallic bond is actually the attraction between the positive nuclei of all the closely packed atoms in the lattice and the electron cloud jointly formed by all the atoms by losing their outermost shell electrons this is by virtue of their low ionization energy.
Physical properties of metals such as malleability, ductility, electrical conductivity, etc can be accounted for by metallic bonds.
