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Following a Labeled Hydrogen in a Transfer 4 questions
Following a Labeled Hydrogen in a Transfer
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A classroom acid–base display uses a water molecule containing one ordinary hydrogen atom, H, and one deuterium atom, D. D is an isotope of hydrogen. In the model the water molecule can transfer either H+ or D+ to NH3. The two electrons of the original oxygen–hydrogen bond stay with oxygen.
| Ion detected after transfer | Contains deuterium |
|---|---|
| NH3D+ | Yes |
| NH4+ | No |
| OH- | No |
| OD- | Yes |
Question 1
Which positive product forms when D⁺ transfers to NH₃?
- NH₃D⁺
- NH₄⁺
- OH⁻
- OD⁻
Question 2
If an NH₄⁺ ion forms from one of the labeled water molecules, which negative ion forms in the same event? Explain where D remains.
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In a test, 20 labeled water molecules each transfer one hydrogen ion to NH3. The model counts 12 NH3D+ ions and 8 NH4+ ions. There are no other reactions.
Question 3
Predict the counts of OH⁻ and OD⁻. Explain how each one corresponds to a positive product.
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Question 4
Explain why measuring the total positive and negative charges would not reveal which isotope moved in a particular event.
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