Aluminum foil I think but if not goodluck :)
Avagadros law states that volume of gas is directly proportional to number of moles of gas at constant pressure and temperature.
where V -volume , n - number of moles
parameters for the first instance are on the left side and parameters for the second instance are on the right side of the equation
substituting these values in the equation
V = 44.8 L
answer is C. 44.8 L
Energy absorbed by Iron block E (iron) = 460.5 J
Energy absorbed by Copper block E (Copper) = 376.8 J
<u>Explanation:</u>
To find the heat absorbed, we can use the formula as,
q = m c ΔT
Here, Mass = m = 10 g = 0.01 kg
ΔT = change in temperature = 400 - 300 = 100 K = 100 - 273 = -173 °C
c = specific heat capacity
c for iron = 460.5 J/kg K
c for copper = 376.8 J/kg K
Plugin the values in the above equation, we will get,
q (iron) = 0.01 kg × 460.5 J/kg K × 100 K
= 460.5 J
q (copper) = 0.01 kg × 376.8 J/kg K × 100 K
= 376.8 J
Answer:
The correct answer is -1085 KJ/mol
Explanation:
To calculate the formation enthalphy of a compound by knowing its lattice energy, you have to draw the Born-Haber cycle step by step until you obtain each element in its gaseous ions. Find attached the correspondent Born-Haber cycle.
In the cycle, Mg(s) is sublimated (ΔHsub= 150 KJ/mol) to Mg(g) and then atoms are ionizated twice (first ionization: ΔH1PI= 735 KJ/mol, second ionization= 1445 KJ/mol) to give the magnesium ions in gaseous state.
By other hand, the covalent bonds in F₂(g) are broken into 2 F(g) (Edis= 154 KJ/mol) and then they are ionizated to give the fluor ions in gaseous state 2 F⁻(g) (2 x ΔHafinity=-328 KJ/mol). The ions together form the solid by lattice energy (ΔElat=-2913 KJ/mol).
The formation enthalphy of MgF₂ is:
ΔHºf= ΔHsub + Edis + ΔH1PI + ΔH2PI + (2 x ΔHaffinity) + ΔElat
ΔHºf= 150 KJ/mol + 154 KJ/mol + 735 KJ/mol + 1445 KJ/mol + (2 x (-328 KJ/mol) + (-2913 KJ/mol).
ΔHºf= -1085 KJ/mol