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:
4.33 L
Explanation:
Step 1: Given data
Initial volume of the balloon (V₁): 3.00 L
Initial pressure of the balloon (P₁): 765 torr
Final volume of the balloon (V₂): ?
Final pressure of the balloon (P₂): 530 torr
Step 2: Calculate the final volume of the balloon
If we consider Helium to behave as an ideal gas, we can calculate the final volume of the balloon using Boyle's law.

that's the answer I think
4 moles as their raport is 4/2 or 2/1
<span>
<span>
</span></span>Volume = 4/3 * PI * r^3
1.59 x 10^24 copper atoms = 2.64 moles of copper
Atomic Mass of copper = 63.55
2.64 * 63.55 = 167.77 grams of copper
Volume of Copper = Mass / Density
Volume of Copper = 167.77 grams / 8.96
Volume of Copper = <span>
<span>
18.72</span></span> cubic centimeters
r^3 = Volume / (4/3 * PI)
r^3 = 18.72 / 4.188
r^3 =
<span>
<span>
<span>
4.47
radius = </span></span></span><span><span><span>1.647</span> centimeters
</span></span>