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:

Explanation:
Hello,
In this case, by considering the mathematical definition of by mass percentage of a solute as shown below:

We are able to compute the mass of the solute in a 20% solution having 500 g of solution as follows:

Best regards.
Hope this helps! Also if it’s hard to read just look up “ what is a protein coat” pretty easy right?
Aluminum can preserve food and drinks longer than iron can. If oxygen combines with the iron the iron will rust and the food or drink inside will not be good to eat anymore and you will have to waste it.