$1.$ True or False $3$ marks

a$.$ On average, hydrogen bonds are weaker than covalent bonds.

b$.$ As climbers approach the summit of a mountain, they usually increase their rate of breathing to compensate of the "thinner air". This increased breathing rate results in a reduction in the CO$2$ levels dissolved in the blood. This will result in an increase in the association of H$++$ HCO$3-->$ H$2$CO$3$ and a decrease in pH$.$

c$.$ The pH of a sample of blood is $7\mathrm{.}4$; the pH of a sample of gastric juice is $1\mathrm{.}4.$ The gastric juice has an $[$H$+]$ that is a million times higher than that of the blood.