Which of the following fertilizers increases the acidity of the soil upon regular use?

Which of the following acts as a Brønsted base?

The conjugate acid of $H_2PO_4^-$ is

The $pK_a$ of acetylsalicylic acid (aspirin) is $3.5$. If the $pH$ of human stomach fluid is $2-3$ and the $pH$ of the small intestine fluid is $8$,then aspirin will:

According to the Bronsted-Lowry concept,an acid is a substance which:

The correct decreasing order of basic strength of $H_2O$,$NH_3$,$OH^{-}$,and $NH_2^{-}$ is: