Answer:
Mass percentage → 0.074 %
[F⁻] = 741 ppm
Explanation:
Aqueous solution of flouride → [F⁻] = 0.0390 M
It means that in 1L of solution, we have 0.0390 moles of F⁻
We need the mass of solution and the mass of 0.0390 moles of F⁻
Mass of solution can be determined by density:
1g/mL = Mass of solution / 1000 mL
Note: 1L = 1000mL
Mass of solution: 1000 g
Moles of F⁻ → 0.0390 moles . 19g /1 mol = 0.741 g
Mass percentage → (Mass of solute / Mass of solution) . 100
(0.741 g / 1000 g) . 100 = 0.074 %
Ppm = mass of solute . 10⁶ / mass of solution (mg/kg)
0.741 g . 1000 mg/1g = 741 mg
1000 g . 1 kg/1000 g = 1kg
741 mg/1kg = 741 ppm
The average kinetic energy of an ideal gas is calculated as
KE_avg = 3/2 kT
where T is the temperature in Kelvin and k=R/N_A; R is the universal gas constant and N_A is the number of moles.
Thus, upon substitution we get
KE_avg = 3/2(8.314/1)(100+273)
KE_avg = 3/2(8.314)(373)
KE_avg = 4651.683
The average kinetic energy of 1 mole of a gas at 100 degree Celsius is 4651.683 J.
Answer:
2.61
Explanation:
pH+pOH=14, so sub in 11.39 for pOH, then subtract it over to get pH=2.61
if you have any questions, leave them in the comments and i will try to answer them, if this helped, pls give brainliest.
