Answer:
2 molecules of water represents 3.32 x 10^-24 moles of water.
Explanation:
To find the solution to this problem, you have to use the concept of Avogadro´s number, that is in 1 mol of any element o compound there are 6.022 x 10^23 molecules. Then,
1 mol H2O ------------- 6.022 x 10^23 molecules
x= 3.32 x 10^-24 ---- 2 molecules.
2 molecules of water represents 3.32 x 10^-24 moles of water.
Answer:
2.64%
Explanation:
mass percent = (grams of solute / grams of solution) x 100
mass percent = (2.4 / 91) × 100
mass percent = 2.64% to 3sf
Answer:
Solving by the method of exponential growth.
bacteria = 2
after one hr = 2² = 4
after 2nd hr = 2³ = 8
after 3rd hr = 2⁴ = 16
after 4th hr = 2⁵ = 32
Answer:
D. Zn → Zn²⁺ + 2e⁻, 2H⁺ + 2e⁻ → H₂.
Explanation:
- It is a redox reaction that is consisted of two half-reactions:
Oxidation reaction:
Zn losses 2 electrons and is oxidized to Zn²⁺:
<em>Zn → Zn²⁺ + 2e⁻.</em>
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Reduction reaction:
H⁺ gains 1 electron and is reduced to H:
<em>2H⁺ + 2e⁻ → H₂.</em>
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<em>So, the right choice is: D. Zn → Zn²⁺ + 2e⁻, 2H⁺ + 2e⁻ → H₂.</em>
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