Answer:
pH = 12.22
Explanation:
<em>... To make up 170mL of solution... The temperature is 25°C...</em>
<em />
The dissolution of Barium Hydroxide, Ba(OH)₂ occurs as follows:
Ba(OH)₂ ⇄ Ba²⁺(aq) + 2OH⁻(aq)
<em>Where 1 mole of barium hydroxide produce 2 moles of hydroxide ion.</em>
<em />
To solve this question we need to convert mass of the hydroxide to moles with its molar mass. Twice these moles are moles of hydroxide ion (Based on the chemical equation). With moles of OH⁻ and the volume we can find [OH⁻] and [H⁺] using Kw. As pH = -log[H⁺], we can solve this problem:
<em>Moles Ba(OH)₂ molar mass: 171.34g/mol</em>
0.240g * (1mol / 171.34g) = 1.4x10⁻³ moles * 2 =
2.80x10⁻³ moles of OH⁻
<em>Molarity [OH⁻] and [H⁺]</em>
2.80x10⁻³ moles of OH⁻ / 0.170L = 0.01648M
As Kw at 25°C is 1x10⁻¹⁴:
Kw = 1x10⁻¹⁴ = [OH⁻] [H⁺]
[H⁺] = Kw / [OH⁻] = 1x10⁻¹⁴/0.01648M = 6.068x10⁻¹³M
<em>pH:</em>
pH = -log [H⁺]
pH = -log [6.068x10⁻¹³M]
<h3>pH = 12.22</h3>
Answer:
1. 0.00040 calories
2. 8.57 calories
3. 0.196 calories
4. 68 calories
5. 243 calories
6. 83680 joules
7. 1,054,368 joules
8. 2.45 calories
9. 556 (it says calories to calories so it wouldn't change)
10. 28367.52 joules
11. 59.6 calories
12. 449.6 joules
13. 0.00234 calories
14. 23292.328 joules
15. 22877693.6 joules
Hope this helps!
Explanation:
Because of the sea waters density. If an object is less dense than the water it would not float
Answer:
Eukarya- Multicellar and unicellar
Explanation:
Fugi- Multicellar
Protista- unicellar
eubacteria- unicellar and have no nucleus
Eukarya is the only option, and that is because Eukarya is both! It contains a nucleus, and a membrane making it the only one that fits into the incomplete graphic! Hope this helps! (I noticed you were waiting for a while so I came to help! <3)
