Answer: B) 46.7% Si and 53.3% O
Explanation:
To calculate the mass percent of element in a given compound, we use the formula:
Mass of quartz = 5.05 g
Mass of silicon = 2.36 g
Mass of oxygen = Mass of quartz - mass of silicon = 5.05g - 2.36 g = 2.69 g
Thus the percentages of silicon and oxygen in quartz are B) 46.7% Si and 53.3% O
Answer:
[S₂] = 1.27×10⁻⁷ M
Explanation:
2 H₂S(g) ⇄ 2 H₂(g) + S₂(g), Kc=1,625x10⁻⁷
The equation of this reaction is:
1,625x10⁻⁷ =
The equilibrium concentrations are:
[H₂S] = 0,162 - 2x
[H₂] = 0,184 + 2x
[S₂] = x
Replacing:
1,625x10⁻⁷ =
Solving:
4x³ + 0,736x² + 0,033856x - 4,3x10⁻⁹
x = 1.27×10⁻⁷
Thus, concentration of S₂ is:
<em>[S₂] = 1.27×10⁻⁷ M</em>