The molality is 0.54 M when 1.34 moles of NaCl is present in 2.47 kg of solvent.
<u>Explanation:</u>
Molality is the measure of how much of amount of solute is dissolved in the solvent. So it is calculated as the ratio of moles of solute to the grams of solvent.
As in this case, the solute is NaCl and solvent is unknown. So the moles of solute is given as 1.34 moles and the mass of solvent is given as 2.47 kg.
Hence, 
Thus, the molality is 0.54 M when 1.34 moles of NaCl is present in 2.47 kg of solvent.
Answer:- oxygen.
Explanations:- The electronic configuration is given and we are asked to figure out the electrically neutral atom that will have the electron configuration, 
.
The sum of electrons for this electron configuration is 8. If we look at the periodic table then 8 is the atomic number of oxygen.
So, the electrically neutral atom for the given electron configuration is oxygen.
Answer:
0.156mol
Explanation:
Number of moles of a substance can be calculated from its mass by dividing its mass by molar mass i.e.
Number of moles (n) = mass/molar mass
Molar mass of PbCl4 is as follows, where Pb = 207.2g/mol, Cl = 35.5g/lol
PbCl4 = 207.2 + 35.5(4)
= 207.2 + 142
= 349.2g/mol
Using: mole = mass/molar mass
mole = 54.32 grams ÷ 349.2g/mol
mole = 0.1555
mole = 0.156mol
