Step-by-step explanation:
The given data is as follows.
= 1 atm,
= 0.78
Now, we will calculate the partial pressure of given nitrogen gas as follows.
![P_{NO_(2)} = X_(2)P_(total)](https://img.qammunity.org/2020/formulas/chemistry/high-school/xjz3ygs7t5ogjjar1mkukl6yx706oyyrcy.png)
=
![0.78 * 0.78](https://img.qammunity.org/2020/formulas/chemistry/high-school/qe63tlv9794euce3f8n26arw1phbcv0sm1.png)
= 0.78 atm
According to the Henry's law we will calculate the solubility of nitrogen as follow.
![S_{N_(2)} = K_(H)P_{N_(2)}](https://img.qammunity.org/2020/formulas/chemistry/high-school/1rm8erhu2kjgmpry555y584db1q7o49opc.png)
=
![6.1 * 10^(-4) M/atm * 0.78 atm](https://img.qammunity.org/2020/formulas/chemistry/high-school/ekp1hr90s54gqpdtmsf3ta2bppx0refnn9.png)
=
![4.758 * 10^(-4) M](https://img.qammunity.org/2020/formulas/chemistry/high-school/u4a940xsjm3avbnkvaj722uwkz3adjcon1.png)
Now, for 99.0 L the amount of nitrogen gas dissolved is calculated as follows.
![(99.0 L N_(2) * 4.758 * 10^(-4) M * 28.0134 g N_(2))/(1 L N_(2) * 1 mol N_(2))](https://img.qammunity.org/2020/formulas/chemistry/high-school/25iy7dvs0q4skyfirm9khmf0opr2qdnj82.png)
=
![13195.49 * 10^(-4)](https://img.qammunity.org/2020/formulas/chemistry/high-school/u0l0bxc9ih6os67s2yy0lhpau8jo0b6c5q.png)
= 1.32 g
Thus, we can conclude that the mass of nitrogen dissolved at room temperature in an 99.0 L home aquarium is 1.32 g.