Answer:
0.26×10²³ molecules
Explanation:
Given data:
Volume of gas = 1.264 L
Temperature = 168°C
Pressure = 946.6 torr
Number of molecules of gas = ?
Solution:
Temperature = 168°C (168+273= 441 K)
Pressure = 946.6 torr (946.6/760 = 1.25 atm)
Now we will determine the number of moles.
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
n = PV/RT
n = 1.25 atm ×1.264 L / 0.0821 atm.L/ mol.K ×441 K
n = 1.58 /36.21 /mol
n = 0.044 mol
Now we will calculate the number of molecules by using Avogadro number.
1 mol = 6.022×10²³ molecules
0.044 mol × 6.022×10²³ molecules/ 1mol
0.26×10²³ molecules
This compound is also known as Barium Carbonate. 1 mole is equal to 1 moles BaCO3, or 197.3359<span> grams.</span>
We use the osmotic pressure to determine the concentration of the solute in the solution. Then, we multiply the volume of the solution to determine the number of moles of solute particles. We need to establish to equations since we have two unknowns, the mass of of each solute. We do as follows:
osmotic pressure = CRT
<span>C = 7.75 / 0.08205 (296.15) = 0.3189 mol / L</span>
<span>moles of particles = C*V = 0.3189*0.250 =0.0797 mol </span>
<span>0.0797 = moles of sucrose + 2*moles of salt </span>
<span>x + 2y = 0.0797 </span>
<span>and </span>
<span>x(MMsucrose) + y(MMNaCl) = 10.2</span>
<span>342x + 58.5y = 10.2
</span>
<span>solve for x and y
</span>
<span>x = 0.0252 mol sucrose</span>
<span>y = 0.0273 mol NaCl
</span>
<span>mass Sucrose = 0.0252(342) = 8.6184 g </span>
<span>mass NaCl = 0.0273(58.5) = 1.5971 g </span>
<span>% NaCl = (1.5971 / 10.2)*100 = 15.66%</span>
