does acidity goes increase or decrease as you go down a group?

[Smooth Operater]

does acidity goes increase or decrease as you go down a group? I forget the trend. Thanks.

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[dudewhensmydat]

Acidity INCREASES as you go from left to right across the periodic table and DECREASES as you go down a group/column.

The opposite is true for Basicity: INCREASES as you go up a group/column and DECREASES as you go from right to left across the periodic table.

 

[joonkimdds]

Acidity INCREASES as you go from left to right across the periodic table and DECREASES as you go down a group/column.

The opposite is true for Basicity: INCREASES as you go up a group/column and DECREASES as you go from right to left across the periodic table.

I think that's wrong.
Acidity increases as u go from left to right is correct.
but it also increases as u go down.

if acidity goes up then basicity goes down so just think of basicity in an opposite way.

It's good to remember the relationship between Ka and pKa.
Big Ka = strong acid = low pKa = low basicity

it's also important to know the order of functional group acidity
COOH>H2O>OH>Alkyne>NH2>Alkene>Alkane

 

[dudewhensmydat]

Joon...

Yes, I see your point about basicity. Thanks for clarifying that.

 

[buffdoctor]

Wait somebody please clarify this. I thought acidity does increase from left to right. But decreases as you go down a column because the groups are less withdrawing. Is this right?

 

[sskater]

Wait somebody please clarify this. I thought acidity does increase from left to right. But decreases as you go down a column because the groups are less withdrawing. Is this right?

Acidity increase left to right because bigger mcl can support a - charge more=lower basicity=higher acidity.

Acidity increase as you down a column for the exact same reason, - charge is balanced out more, more stable base, increased acidity.

 

[dent777]

Always have a reference in mind when comparing acids. HF is a weak acid and HCl, HBr, HI are strong by definition. Therefore, acidity increases as you go down and HI is the strongest. In addition think of strongest acids, HCl, HBr, and HI which means that acidity increases as you move from left to right i.e towards strong acids.
Opposite trend for bases

 

[buffdoctor]

Gotcha. Makes sense guys. Thanks!

 

[JDHK]

whether the solution is protic or aprotic matters right?

 

[dent777]

whether the solution is protic or aprotic matters right?

You are confusing nucleophile strength with acidity. If the question asks which of following is the strongest nucleophile, then it would make a difference whether it is protic or aprotic.