Answer:
78 moles of the solute
Explanation:
From the question;
- Molarity of the solution is 6.50 M
- Volume of the solution is 12.0 L
We want to determine the number of moles needed
We need to know that;
Molarity = Number of moles ÷ Volume
Therefore;
Number of moles = Molarity × Volume
Hence;
Number of moles = 6.50 M × 12.0 L
= 78 moles
Thus, the moles of the solute needed is 78 moles
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
Answer:
No weapons or drugs. Having responsible teachers
(6.0×10^4) = 60,000
(3.1×10^-1) = 0.31
60,000 × 0.31 = 18,600
Answer: 17.6×10^-3g of CO2
Explanation:
We first look at the stoichiometry of the balanced reaction equation. One mole of methane produces one mole of carbon dioxide. Hence 16g of methane yields 44g of carbon dioxide. If we now composed this with the given 6.40×10^-3g of methane as shown in the solution attached, we obtain the answer stated above.
