Answer: 310.7 grams
Explanation:
Multiply the two values so the units of mL cancel and you get grams
2.545*122.1 = 310.7 grams
On Earth it is relatively rare—5.2 ppm by volume in the atmosphere. Most terrestrial helium<span> present today is created by the natural radioactive decay of heavy radioactive elements (thorium and uranium, although there are other examples), as the alpha particles emitted by such decays consist of </span>helium<span>-4 nuclei.</span>
1.50 moles H20(6.02*10^23 molecules/1 mole)
9.03*10^23 molecules
The minimum volume of water needed is 0.28 mL. The solution will have
1.7 mg of phthalic acid remaining in solution.
<em>At 100 °C</em>
Volume of water required = 50 mg HPh × (100 mL water/18 000 mg HPh)
= 0.28 mL water
<em>At 25 °C
</em>
Mass of HPh in solution = 0.28 mL water × (620 mg HPh/100 mg water)
= 1.7 mg HPh
Answer:
pH = 12.6
Explanation:
The HF reacts with LiOH as follows:
HF + LiOH → LiF + H₂O
To solve this question we need to find the moles of each reactant:
<em>Moles HF:</em>
0.1500L * (0.20mol / L) = 0.030 moles HF
<em>Moles LiOH:</em>
0.600L * (0.10mol / L) = 0.060 moles LiOH
That means there is an amount of LiOH in excess, that is:
0.060 mol - 0.030 mol = 0.030 moles LiOH
In 600.0mL + 150.0mL = 750.0mL = 0.750L
The molarity of LiOH is:
0.030 moles LiOH / 0.750L =
0.040M LiOH = [OH⁻]
As:
Kw = 1x10⁻¹⁴ = [H⁺] [OH⁻]
1x10⁻¹⁴ = [H⁺] [0.040M]
2.5x10⁻¹³M = [H⁺]
As pH = -log [H⁺]
<h3>pH = 12.6</h3>
