Answer:
1. Phenolphthalein
2. Phenolphthalein
3. Methyl orange
Explanation:
Different indicators are used by knowing the relative strength of the acid and the bases I.e whether the acid is strong or weak, so also the base.
The following answers are obtainable:
1. Phenolphthalein
We use this indicator for a weak base and a strong acid. Formic acid is a weak organic acid while sodium hydroxide is a strong base
2. Phenolphthalein
We use this indicator because we are dealing with a strong acid and a strong base. Hydrochloric acid is a strong acid while potassium hydroxide is a strong base
3. Methyl orange
This is because we are dealing with a strong acid and a weak base
The question is incomplete. Complete question is
<span>In an aqueus solution, which substance yields hydrogen ions as the only positive ions in the solution? 1)NaH 2)HCOOH 3)LiOH 4) CH3CH2OH?
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Answer: Correct answer is option 2, HCOOH
Reason:
HCOOH is a formic acid. When mixed in water, it undergoes dissociation which can be represented as
HCOOH </span>↔ HCOO- + H+
The compound NaH, will generate hydride ion (H-), while LiOH is an ionic compound, hence when dissolved in water it generated OH- ions. The compound CH3CH2OH is named as ethyl alcohol. This compound donot dissociate in aqueous medium.
Answer:
The element is oxygen.
1s² 2s² 2p⁴
Explanation:
Let's consider the electron configuration of the excited state.
1s² 2s² 2p³ 3s¹
According to the Aufbau principle, the electron in 3s should occupy the shell with lower energy. The ground-state electron configuration is:
1s² 2s² 2p⁴
The differential electron is in the level 2. Then, the element is in the period 2.
The electrons in the last level are 2 + 4 = 6. Then, the element is in the group VIA or 16.
The element is oxygen.
Answer:
Are you just trying to give free points? If not remove my answer and tell me what I did wrong ok?
Explanation:
