Given mass of gas has a volume of 7.5 dm³ at 250k and 80kNm⁻² (calculate it which it will have feature 7.2 Jums at 270k)

Initial conditions (State 1):
Pressure $P_1 = 80 \, \text{kN/m}^2$
Volume $V_1 = 7.5 \, \text{dm}^3$
Temperature $T_1 = 250 \, \text{K}$

Final conditions (State 2):
Pressure $P_2 = ?$
Volume $V_2 = 7.2 \, \text{dm}^3$
Temperature $T_2 = 270 \, \text{K}$

The Combined Gas Law states that for a fixed amount of gas:

$$\frac{P_1 V_1}{T_1} = \frac{P_2 V_2}{T_2}$$

$$P_2 = \frac{(80 \, \text{kN/m}^2) \cdot (7.5 \, \text{dm}^3) \cdot (270 \, \text{K})}{(250 \, \text{K}) \cdot (7.2 \, \text{dm}^3)}$$ $$P_2 = \frac{80 \times 7.5 \times 270}{250 \times 7.2} \, \text{kN/m}^2$$ $$P_2 = \frac{162000}{1800} \, \text{kN/m}^2$$ $$P_2 = 90 \, \text{kN/m}^2$$

The pressure at which the gas will have a volume of $7.2 \, \text{dm}^3$ at $270 \, \text{K}$ is $\boxed{90 \, \text{kN/m}^2}$.