Answer:
17.51M
Explanation:
first we make out what we've been given .
Mass of ethanol= 91.9g
volume of water = 481.0ml
volume of solution= 597.5ml
density of water = 1.0g/ml
density of ethanol= 0.789g/ml.
firstly find the volume of ethanol since the total volume of the solution is 597.5ml and we've been given the volume of water which is 481.0ml , we subtract the volume of water from the volume of the solution , to find out the volume of ethanol .
volume e =597.5ml - 481.0ml
= 116.5ml
Then we find the molecular mass of ethanol , which is 45.04g/mol .
then we find the number of moles of ethanol .
n=mass /molar mass
=91.9g/ 45.04g/mol
=2.04mols .
Then convert the volume from milliliters to liters , by dividing by a 1000 .
v= 116.5/1000
=0.1165L
since we have our number of moles and volume , we can now find the molarity . which is
M=n/v
= 2.04mols /0.1165L
= 17.51M .
Answer:
Mass of lead, m = 687 g
Explanation:
The expression for the calculation of the enthalpy change of a process is shown below as:-
Where,
is the enthalpy change
m is the mass
C is the specific heat capacity
is the temperature change
Thus, given that:-
Mass = ?
Specific heat = 0.0380 cal/g°C
Heat added = 47.0 calories
So,
Mass of lead, m = 687 g
Answer:
The density of a material given is <u>1.55 g/mL</u>
Explanation:
Density = Mass per unit volume of the substance .
![Density=\frac{mass}{Volume}](https://tex.z-dn.net/?f=Density%3D%5Cfrac%7Bmass%7D%7BVolume%7D)
Initial Volume of water = 47.54 mL
Total volume = Volume of water + material = 50.78 mL
Volume of material = Total volume - volume of water
Volume of material = 50.78 - 47.54 = 3.24 mL
Volume of material = 3.24 mL
Mass of the material = 5.03 g
![Density=\frac{mass}{Volume}](https://tex.z-dn.net/?f=Density%3D%5Cfrac%7Bmass%7D%7BVolume%7D)
![Density=\frac{5.03}{3.24}](https://tex.z-dn.net/?f=Density%3D%5Cfrac%7B5.03%7D%7B3.24%7D)
![Density = 1.55g/mL](https://tex.z-dn.net/?f=Density%20%3D%201.55g%2FmL)
The density of a material given is <u>1.55 g/mL</u>
Answer:
Vapor pressure of solution = 23.9 Torr
Explanation:
Let's apply the colligative poperty of vapor pressure to solve this:
ΔP = P° . Xm
ΔP = Vapor pressure of pure solvent - Vapor pressure of solution
We have solvent and solute mass, so let's find out the moles of each.
55.3 g / 62 g/mol = 0.89 moles
285.2 g / 18 g/mol = 15.84 moles
Let's determine the mole fraction of ethylene glycol.
Mole fraction = Moles of ethylene glyco / Total moles
0.89 moles / (0.89 + 15.84) = 0.053
25.3 Torr - Vapor pressure of solution = 25.3 Torr . 0.053
Vapor pressure of solution = 25.3 Torr . 0.053 - 25.3 Torr
Vapor pressure of solution = 23.9 Torr