Final answer:
To calculate ΔG at -1.9°C, use the equation ΔG = ΔH - TΔS. Convert the temperature from Celsius to Kelvin. Substitute the values into the equation and calculate.
Step-by-step explanation:
To calculate ΔG at -1.9°C, you can use the equation ΔG = ΔH - TΔS. First, convert the temperature from Celsius to Kelvin by adding 273.15, so -1.9°C becomes 271.25 K. Then substitute the values into the equation: ΔG = 65.13 - (271.25 K)(645.37 J/(K·mol)). Calculate the product and you will get the value of ΔG at -1.9°C.