Answer:
d. 127 g/mol.
Explanation:
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In this case, since we have the amount of molecules of this this compound, we are able to compute the moles out there by using the Avogadro's number:

Which correspond to the moles of X2. Then, by using the mass we are able to compute the molar mass of X2:

It means that the atomic mass of X halves the molar mass of X2, which is then d. 127 g/mol.
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Answer:
148.04 kJ/mol
Explanation:
Let's consider the following thermochemical equation.
NO(g) + 1/2 O₂(g) → NO₂(g) ΔH°rxn = -114.14 kJ/mol
We can find the standard enthalpy of formation (ΔH°f) of NO(g) using the following expression.
ΔH°rxn = 1 mol × ΔH°f(NO₂(g)) - 1 mol × ΔH°f(NO(g)) - 1/2 mol × ΔH°f(O₂(g))
ΔH°f(NO(g)) = 1 mol × ΔH°f(NO₂(g)) - ΔH°rxn - 1/2 mol × ΔH°f(O₂(g)) / 1 mol
ΔH°f(NO(g)) = 1 mol × 33.90 kJ/mol - (-114.14 kJ) - 1/2 mol × 0 kJ/mol / 1 mol
ΔH°f(NO(g)) = 148.04 kJ/mol
Answer:
Helium, Neon, Argon, Krypton, Xenon, Radon, and Oganesson
Explanation:
they have full outer shells
Moles of gas = 0.369
<h3>Further explanation</h3>
Given
P = 2 atm
V = 5.3 L
T = 350 L
Required
moles of gas
Solution
Ideal gas Law

Avogadro's law : at the same temperature and pressure, the ratio of gas volume will be equal to the ratio of gas moles
moles of O₂ = 45% x 0.369 = 0.166
moles of Ar = 12% x 0.369 = 0.044
moles of N = 43% x 0.369 = 0.159
The pH of the resulting solution is 2.82.
<h3>What is pH ?</h3>
pH is the measure of acidity and alkalinity of a solution , It has a range of 1 to 14.
HCl + NaOH → NaCl + H₂O
0.0040 .0025 0 0
0.0040 -0.0025 0 0.0025 0.0025
Moles of HCl = 0.0015
As 0.0025 moles of NaOH reacts with 0.0025 moles of HCl leaving behind 0.0015 moles of HCl
Concentration of HCl = 0.0015/ 1 = 0.0015 M
[ H⁺] = 0.0015 M
pH = -log [ H⁺]
pH = -log [ 0.0015]
pH = 2.82
Therefore the pH of the resulting solution is 2.82.
To know more about pH
brainly.com/question/15289741
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