Explanation:
Magnesium has atomic number 12. It will be distributed in K, L, M shell in the following way:
K shell can accommodate a maximum of 2 electrons.
L shell can accommodate a maximum of 8 electrons and
M shell will accommodate 2 electrons
So the configuration becomes 2, 8,3
1 moles -------- 6.02x10²³ atoms
?? moles ----- 7.4x10²¹ atoms
moles = 7.4x10²¹ / 6.02x10²³
= 0.01229 moles
hope this helps!
Answer:
0.54 mole of H2O.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2CH3OH + 3O2 —> 2CO2 + 4H2O
From the balanced equation above,
2 moles of CH3OH reacted to produce 4 moles of water.
Finally, we shall determine the number of mole of water (H2O) produced by the reaction of 0.27 moles of CH3OH. This can be obtained as follow:
From the balanced equation above,
2 moles of CH3OH reacted to produce 4 moles of water.
Therefore, 0.27 moles of CH3OH will react to produce = (0.27 × 4)/2 = 0.54 mole of H2O.
Thus, 0.54 mole of H2O is produced from the reaction.
To determine the molar mass of the unknown gas, we use Graham's Law of Effusion where it relates the effusion rates of two gases with their molar masses. It is expressed as r1/r2 = √M2/M1. We calculate as follows:
Let 1 = argon gas
2 = unknown gas
r2 = 0.91r1
r1/r2 = 1/0.91
1/0.91 = √M2/M1 = √M2/40
M2 = 48.30 g/mol
