Answer:
2g
Explanation:
2 half-lives will pass. Therefore the amount will be quartered into 2g.
Answer:
The concentration of [Ca²⁺] is 8.47 x 10⁻³ M
Explanation:
We consider the solubility of hydroxyapatite,
Ca₁₀(PO₄)₆(OH)₂ ⇔ 10Ca²⁺ + 6PO₄³⁻ + 2 OH⁻
Assumed that there is <em>a</em> mol of hydoxyapatite disolved in water, yielding <em>10a</em> mol Ca²⁺ of and <em>6a</em> mol of PO₄³⁻
We also have Ksp equation,
Ksp = [Ca²⁺]¹⁰ x [PO₄³⁻]⁶ x [OH⁻]² = 2.34 x 10⁻⁵⁹
⇔ 10a¹⁰ x 6a⁶ x (5.30 x 10⁻⁶)² = 2.24 x 10⁻⁵⁹
⇔ 60a¹⁶ = 2.24 x 10⁻⁵⁹ / 5.30 x 10⁻¹²
⇔ a¹⁶ = 0.007 x 10⁻⁴⁷ = 7 x 10⁻⁵⁰
⇔ a =
= 8.47 x 10⁻⁴
Hence,
[Ca²⁺] = 10<em>a</em> = 8.47 x 10⁻³ M
Answer:
53.87g
Explanation:
Given parameters:
Percentage by mass of Nitrogen in fertilizer = 19%
Mass of fertilizer = 10.0oz
Unkown:
Mass in grams of Nitrogen in the container = ?
Solution
To solve this problem, we first find the percentage of mass of nitrogen in the fertilizer by a taking a percentage of the given mass of the fertlilizer:
Mass of Nitrogen in ounces of the fertilizer =
x 10 = 1.9oz
Since we are expected to express this in grams:
1oz = 28.35g
1.9oz = 1.9 x 28.35, 53.87g