Question

which one of the following species is a base?
oh-
h2o2
nh4+
ch3cooh

question 2
match the compound formula and its type (acid, base, amphiprotic species).
h3po4 choose
nh3 choose
h2po4- choose

Explanation:

Step1: Recall base - definition

A base is a substance that can accept a proton ($H^+$).

Step2: Analyze each species in Question 1

• $OH^-$ can accept a proton to form $H_2O$, so it is a base.
• $H_2O_2$ is a peroxide and not a base in the context of proton - transfer.
• $NH_4^+$ is a cation and can donate a proton, it is an acid.
• $CH_3COOH$ is acetic acid and donates a proton.

Step3: Analyze compounds in Question 2

• $H_3PO_4$ (phosphoric acid) can donate protons, so it is an acid.
• $NH_3$ (ammonia) can accept a proton to form $NH_4^+$, so it is a base.
• $H_2PO_4^-$ can donate a proton to form $HPO_4^{2 - }$ and can also accept a proton to form $H_3PO_4$, so it is an amphiprotic species.

Answer:

Question 1: $OH^-$
Question 2:
$H_3PO_4$: Acid
$NH_3$: Base
$H_2PO_4^-$: Amphiprotic species