Bronsted Lowry Acid Base Worksheet - Fill Online, Printable ... - Free Printable

To find the conjugate acid-base pairs, we need to look at what happens to each molecule in the reaction:
* Acid: Donates a proton ($H^+$). It turns into its conjugate base.
* Base: Accepts a proton ($H^+$). It turns into its conjugate acid.

A conjugate pair always differs by exactly one hydrogen ion ($H^+$).

Here are the pairs for each reaction:

1.) $HCO_3^- + NH_3 \rightarrow CO_3^{-2} + NH_4^+$
* $HCO_3^-$ loses an $H^+$ to become $CO_3^{-2}$. (Pair: $HCO_3^- / CO_3^{-2}$)
* $NH_3$ gains an $H^+$ to become $NH_4^+$. (Pair: $NH_3 / NH_4^+$)

2.) $HCl + H_2O \rightarrow H_3O^+ + Cl^-$
* $HCl$ loses an $H^+$ to become $Cl^-$. (Pair: $HCl / Cl^-$)
* $H_2O$ gains an $H^+$ to become $H_3O^+$. (Pair: $H_2O / H_3O^+$)

3.) $CH_3COOH + H_2O \rightarrow H_3O^+ + CH_3COO^-$
* $CH_3COOH$ loses an $H^+$ to become $CH_3COO^-$. (Pair: $CH_3COOH / CH_3COO^-$)
* $H_2O$ gains an $H^+$ to become $H_3O^+$. (Pair: $H_2O / H_3O^+$)

4.) $HOCl + NH_3 \rightarrow NH_4^+ + ClO^-$
* $HOCl$ loses an $H^+$ to become $ClO^-$. (Pair: $HOCl / ClO^-$)
* $NH_3$ gains an $H^+$ to become $NH_4^+$. (Pair: $NH_3 / NH_4^+$)

5.) $H_2SO_4 + OH^- \rightarrow HSO_4^- + H_2O$
* $H_2SO_4$ loses an $H^+$ to become $HSO_4^-$. (Pair: $H_2SO_4 / HSO_4^-$)
* $OH^-$ gains an $H^+$ to become $H_2O$. (Pair: $OH^- / H_2O$)

6.) $H_2SO_4 + H_2O \rightarrow H_3O^+ + HSO_4^-$
* $H_2SO_4$ loses an $H^+$ to become $HSO_4^-$. (Pair: $H_2SO_4 / HSO_4^-$)
* $H_2O$ gains an $H^+$ to become $H_3O^+$. (Pair: $H_2O / H_3O^+$)

7.) $CO_3^{-2} + H_2O \rightarrow HCO_3^- + OH^-$
* $H_2O$ acts as the acid and loses an $H^+$ to become $OH^-$. (Pair: $H_2O / OH^-$)
* $CO_3^{-2}$ acts as the base and gains an $H^+$ to become $HCO_3^-$. (Pair: $CO_3^{-2} / HCO_3^-$)

8.) $NH_4^+ + OH^- \rightarrow NH_3 + H_2O$
* $NH_4^+$ loses an $H^+$ to become $NH_3$. (Pair: $NH_4^+ / NH_3$)
* $OH^-$ gains an $H^+$ to become $H_2O$. (Pair: $OH^- / H_2O$)

9.) $HCOOH + CH_3COO^- \rightarrow HCOO^- + CH_3COOH$
* $HCOOH$ loses an $H^+$ to become $HCOO^-$. (Pair: $HCOOH / HCOO^-$)
* $CH_3COO^-$ gains an $H^+$ to become $CH_3COOH$. (Pair: $CH_3COO^- / CH_3COOH$)

10.) $HCN + H_2O \rightarrow CN^- + H_3O^+$
* $HCN$ loses an $H^+$ to become $CN^-$. (Pair: $HCN / CN^-$)
* $H_2O$ gains an $H^+$ to become $H_3O^+$. (Pair: $H_2O / H_3O^+$)

11.) $C_6H_5NH_2 + H_2O \rightarrow C_6H_5NH_3^+ + OH^-$
* $H_2O$ acts as the acid and loses an $H^+$ to become $OH^-$. (Pair: $H_2O / OH^-$)
* $C_6H_5NH_2$ acts as the base and gains an $H^+$ to become $C_6H_5NH_3^+$. (Pair: $C_6H_5NH_2 / C_6H_5NH_3^+$)

12.) $H_2O + H_2O \rightarrow H_3O^+ + OH^-$
* One water molecule acts as an acid ($H_2O / OH^-$).
* The other water molecule acts as a base ($H_2O / H_3O^+$).

13.) $HSO_4^- + H_2O \rightarrow SO_4^{-2} + H_3O^+$
* $HSO_4^-$ loses an $H^+$ to become $SO_4^{-2}$. (Pair: $HSO_4^- / SO_4^{-2}$)
* $H_2O$ gains an $H^+$ to become $H_3O^+$. (Pair: $H_2O / H_3O^+$)

14.) $OH^- + H_3O^+ \rightarrow H_2O + H_2O$
* $H_3O^+$ loses an $H^+$ to become $H_2O$. (Pair: $H_3O^+ / H_2O$)
* $OH^-$ gains an $H^+$ to become $H_2O$. (Pair: $OH^- / H_2O$)

15.) $NH_3 + H_2O \rightarrow NH_4^+ + OH^-$
* $H_2O$ acts as the acid and loses an $H^+$ to become $OH^-$. (Pair: $H_2O / OH^-$)
* $NH_3$ acts as the base and gains an $H^+$ to become $NH_4^+$. (Pair: $NH_3 / NH_4^+$)

Final Answer:
1. Acid/Base: $HCO_3^-$ / Base/Acid: $NH_3$ $\rightarrow$ Conj Base: $CO_3^{-2}$ / Conj Acid: $NH_4^+$
* Pairs: ($HCO_3^-$, $CO_3^{-2}$) and ($NH_3$, $NH_4^+$)
2. Pairs: ($HCl$, $Cl^-$) and ($H_2O$, $H_3O^+$)
3. Pairs: ($CH_3COOH$, $CH_3COO^-$) and ($H_2O$, $H_3O^+$)
4. Pairs: ($HOCl$, $ClO^-$) and ($NH_3$, $NH_4^+$)
5. Pairs: ($H_2SO_4$, $HSO_4^-$) and ($OH^-$, $H_2O$)
6. Pairs: ($H_2SO_4$, $HSO_4^-$) and ($H_2O$, $H_3O^+$)
7. Pairs: ($H_2O$, $OH^-$) and ($CO_3^{-2}$, $HCO_3^-$)
8. Pairs: ($NH_4^+$, $NH_3$) and ($OH^-$, $H_2O$)
9. Pairs: ($HCOOH$, $HCOO^-$) and ($CH_3COO^-$, $CH_3COOH$)
10. Pairs: ($HCN$, $CN^-$) and ($H_2O$, $H_3O^+$)
11. Pairs: ($H_2O$, $OH^-$) and ($C_6H_5NH_2$, $C_6H_5NH_3^+$)
12. Pairs: ($H_2O$, $OH^-$) and ($H_2O$, $H_3O^+$)
13. Pairs: ($HSO_4^-$, $SO_4^{-2}$) and ($H_2O$, $H_3O^+$)
14. Pairs: ($H_3O^+$, $H_2O$) and ($OH^-$, $H_2O$)
15. Pairs: ($H_2O$, $OH^-$) and ($NH_3$, $NH_4^+$)