Answer:
![m=0.512m](https://img.qammunity.org/2021/formulas/chemistry/college/b13quz12uycvogfd01tay6spetcyu35ln7.png)
Step-by-step explanation:
Hello,
In this case, we can consider the n-propanol as the solute (lower amount) and the t-butanol as the solvent (higher amount), for which, initially, we must compute the moles of n-propanol (molar mass = 60.1 g/mol) as shown below:
![n_(solute)=0.400g*(1mol)/(60.1g0)=6.656x10^(-3)mol](https://img.qammunity.org/2021/formulas/chemistry/college/90a52bq4ga3sfgyceag0zihok1tznq7d8e.png)
Since the molality is computed via:
![m=(n_(solute))/(m_(solvent))](https://img.qammunity.org/2021/formulas/chemistry/college/pez19o75tfmc0s2dd1ebbkeuq3korbsmzp.png)
Whereas the mass of the solvent is used in kilograms (0.0130g for the given one). Thus, we compute the resulting molality of the solution:
![m=(6.656x10^(-3)mol)/(0.0130kg)\\ \\m=0.512(mol)/(kg)](https://img.qammunity.org/2021/formulas/chemistry/college/emet7nhhk0ogfddx8wc593c4tynus5dao5.png)
Or just:
![m=0.512m](https://img.qammunity.org/2021/formulas/chemistry/college/b13quz12uycvogfd01tay6spetcyu35ln7.png)
Best regards.