Answer:
4. 15
Explanation:
The given formula is:-
1 mole of the salt contains 2 moles of nitrogen atom, 8 moles of hydrogen, 1 mole of sulfur and 4 moles of oxygen atom as can be seen from the formula.
Thus,
1 mole of salt contains total of 15 moles of the atoms which constitute the salt.
<u>Hence, 4. is the answer.</u>
Answer:
The vapor pressure of the solution is 23.636 torr
Explanation:
Where;
is the vapor pressure of the solution
is the mole fraction of the solvent
is the vapor pressure of the pure solvent
Thus,
15.27 g of NaCl = [(15.27)/(58.5)]moles = 0.261 moles of NaCl
0.67 kg of water = [(0.67*1000)/(18)]moles = 37.222 moles of H₂O
Mole fraction of solvent (water) = (number of moles of water)/(total number of moles present in solution)
Mole fraction of solvent (water) = (37.222)/(37.222+0.261)
Mole fraction of solvent (water) = 0.993
<u>Note:</u> the vapor pressure of water at 25°C is 0.0313 atm
Therefore, the vapor pressure of the solution = 0.993 * 0.0313 atm
the vapor pressure of the solution = 0.0311 atm = 23.636 torr