list from strongest acid to weakest acid

HC(triple bond)CCH3
H2C=CH2
H3CNH2
CH4
H2O

i thought the order went
HC(triple)CCH3
H3CNH2
H2O
H2C=CH2
CH4

but it comes out as wrong and i don't know why >

H2O >HC(triple)CCH3 >H3CNH2 >H2C=CH2 >CH4

I'm not sure why H2O is 1st but this is the answer i got in my sapling

To determine the relative strengths of acids, we need to consider a few factors: the stability of the conjugate base, the polarity of the bond, and the acidity of the hydrogen atom. Let's analyze each compound to determine their acid strengths:

1. HC≡CCH3 (ethyne/acetylene):
This compound has a triple bond between carbon atoms. The acidity here is due to the sp hybridization of the carbon atom and the increased s-character of the hybrid orbital, leading to greater electronegative pull on the hydrogen atom. Therefore, HC≡CCH3 is the strongest acid in this list.

2. H2C=CH2 (ethylene):
Although ethylene consists of a double bond, the hydrogen atom attached to a sp2 carbon is less acidic than the hydrogen atom attached to an sp hybridized carbon. The carbon-carbon double bond leads to some electron delocalization, reducing the acidity compared to HC≡CCH3.

3. H3CNH2 (methylamine):
In this case, the hydrogen atom is attached to an electronegative nitrogen atom. However, the presence of the lone pair on nitrogen makes it a weaker acid than the previous compounds.

4. H2O (water):
Water is a weak acid compared to the compounds above. The acidity is due to the partial positive charge on the hydrogen atom caused by the high electronegativity of oxygen.

5. CH4 (methane):
Methane is the weakest acid in this list since it does not have any electronegative atoms capable of stabilizing the negative charge on the conjugate base.

Based on the analysis above, the correct order from strongest to weakest acid is:
HC≡CCH3 > H2C=CH2 > H3CNH2 > H2O > CH4

The acidity of a compound is determined by the stability of the resulting conjugate base after the acid has donated its proton. In general, the strength of an acid increases with the stability of its conjugate base.

In the given list, the correct order of the compounds from strongest acid to weakest acid is:

1. HC(triple bond)CCH3: This compound, also known as ethynylmethane, is a terminal alkyne. The acidity of the terminal alkyne is higher due to the presence of the highly electronegative sp carbon which can stabilize the negative charge of the conjugate base. Therefore, HC(triple bond)CCH3 is the strongest acid in the list.

2. H3CNH2: This compound is known as methylamine. Although less acidic than HC(triple bond)CCH3, it is still a moderately strong acid because the lone pair on the nitrogen can stabilize the resulting conjugate base.

3. H2O: Water is a weak acid because it can donate a proton but not very easily. Its conjugate base, the hydroxide ion (OH-), is more stable due to resonance with the oxygen lone pairs.

4. H2C=CH2: This compound is ethene, an alkene. Alkenes are generally weakly acidic as the resulting negative charge is delocalized through pi bonding.

5. CH4: Methane is a non-acidic compound. It does not have an acidic proton and cannot donate a proton.

So, the correct order from strongest acid to weakest acid is HC(triple bond)CCH3, H3CNH2, H2O, H2C=CH2, CH4.