Respuesta :
Answer:
5.46 M
Explanation:
First, we need to know the molar mass of the citric acid, the molar masses of the elements are:
H = 1 g/mol
C = 12 g/mol
O = 16 g/mol
So the molar mass of the acid is: 8x1 + 6x12 + 7x16 = 192 g/mol
The mass of the acid is the number of moles multiplied by the molar mass, so:
m = 0.688x192 = 132.096 g
Then, the volume is the mass divided by the concentration:
V = 132.096/1.049 = 125.926 mL = 0.1259 L
So, the molar concentration is the number of moles divided by the volume in liters:
M = 0.688/0.1259
M = 5.46 M
Answer:
[tex]M=0.637[/tex]
Explanation:
For this question, we have to assume that we have 1 L of solvent. With the molality equation we can calculate the moles of solute, so:
[tex]moles~=~m*L=~0.688*1=0.688~moles[/tex]
Then we can calculate the grams of solute using the molar mass :
molar mass of [tex]H_3C_6H_5O_7[/tex]=192.12 g/mol
[tex]0.688~mol\frac{192.12~g}{1~mol}=132.17~g[/tex]
The density for water is 1 Kg/L, therefore 1 L of water equal to 1 Kg, the total mass of the solution would be:
1000 g + 132.17 g = 1132.17 g
With this value we can calculate the volume of the solution using the density, so:
[tex]1132.17~g\frac{1~mL}{1.049~g}\frac{1~L}{1000~mL}=1.079~L[/tex]
Finally, we can calculate the molarity diving the moles by the volume, so:
[tex]M=\frac{0.688}{1.079}=0.637[/tex]