Answer:
![M_(base)=0.14M](https://img.qammunity.org/2021/formulas/chemistry/high-school/tn68p7dbarbwpouj8xytcuiq1f8sso13is.png)
Step-by-step explanation:
Hello,
In this case, the first step is to compute the oxalic acid dihydrate's moles as shown below, considering its molar mass as 126 g/mol:
![n_(acid)=(0.647g)/(126 g/mol) =0.00513mol](https://img.qammunity.org/2021/formulas/chemistry/high-school/u178k3kx4p4i5aumkyy6xlh917mntexnld.png)
Now, since the undergoing chemical reaction is:
![Ba(OH)_2+H_2C_2O_4\rightarrow BaC_2O_4+2H_2O](https://img.qammunity.org/2021/formulas/chemistry/high-school/vm3jttrb9wm6xdikh9574kj2l5dwekirk3.png)
Their molar relationship is 1 to 1, therefore:
![n_(acid)=n_(base)](https://img.qammunity.org/2021/formulas/chemistry/high-school/c497c57zrzdor879cbf4fk4lkq1qvciqsi.png)
Thus, the barium hydroxide's molarity turns out:
![M_(base)=(0.00513mol)/(0.0359L)=0.14M](https://img.qammunity.org/2021/formulas/chemistry/high-school/73nn35aqvvc6txma0tz7emkzk622gfo5hv.png)
Best regards.