Answer:
1.70
Explanation:
The molar mass of perchloric acid is 100.46 g/mol. The moles corresponding to 484 mg (0.484 g) are:
0.484 g × (1 mol/100.46 g) = 4.82 × 10⁻³ mol
4.82 × 10⁻³ moles are dissolved in 240 mL (0.240 L) of solution. The molar concentration of perchloric acid is:
4.82 × 10⁻³ mol/0.240 L = 0.0201 M
Perchloric acid is a strong monoprotic acid, that is, it dissociates completely, so [H⁺] = 0.0201 M.
The pH is:
pH = -log [H⁺] = -log 0.0201 = 1.70
The number of atoms of gold in the pure ring are 7.18 × 10²² atoms.
<h3>HOW TO CALCULATE NUMBER OF ATOMS?</h3>
The number of atoms in a substance can be calculated by multiplying the number of moles of the substance by Avogadro's number.
The number of moles in the gold (Au) can be calculated by dividing the mass of gold by its molar mass (196.97g/mol).
no. of moles = 23.5g ÷ 196.97g/mol
no. of moles = 0.119mol
Number of atoms in Au = 0.119 × 6.02 × 10²³
no. of atoms = 7.18 × 10²² atoms.
Therefore, the number of atoms of gold in the pure ring are 7.18 × 10²² atoms.
Learn more about number of atoms at: brainly.com/question/15959704
my answer is D sorry if I'm wrong
Answer:
12
Explanation:
Boyles law
P1 (.36)
V1(28.3)
P2(.85)
V2(?)
P1*V1=P2*V2
plug it in, and you get 12