Question

1995 2000 2005 2010 2015 2020 ph 8.31 8.22 8.17 8.08 8.02 7.95 percent co₃²⁻ 20% 18% 15% 12% 11% 10% dic (μmol/kg) 1903 2043 2090 2167 2212 2251 pco₂ (ppm) 355 364 371 389 395 414 co₂ + h₂o ⇌ h₂co₃ h₂co₃ ⇌ hco₃⁻ + h⁺ hco₃⁻ ⇌ co₃²⁻ + h⁺ which of these statements are supported by the data? you can select more than one. co₃²⁻ increased because dic increased. co₃²⁻ decreased because ph decreased. ph decreased because pco₂ increased. dic increased because ph increased.

Explanation:

1. Looking at the data, the percentage of $\text{CO}_3^{2 -}$ decreased over the years while DIC increased, so the statement " $\text{CO}_3^{2 -}$ increased because DIC increased" is not supported.
2. As pH decreased from 8.31 in 1995 to 7.95 in 2020, the percentage of $\text{CO}_3^{2 -}$ also decreased from 20% to 10%, indicating that $\text{CO}_3^{2 -}$ decreased because pH decreased.
3. As $p\text{CO}_2$ increased from 355 ppm in 1995 to 414 ppm in 2020, pH decreased from 8.31 to 7.95, showing that pH decreased because $p\text{CO}_2$ increased.
4. DIC increased over the years while pH decreased, so the statement "DIC increased because pH increased" is not supported.

Answer:

B. $\text{CO}_3^{2 -}$ decreased because pH decreased.
C. pH decreased because $p\text{CO}_2$ increased.