Answer:
[tex]m_{KOH}= 142.0gKOH[/tex]
Explanation:
Hello there!
In this case, according to the following chemical reaction we found on goo gle as it was not given:
[tex]2MnO_2+4KOH+O_2\rightarrow 2KMnO4+2KOH+H_2[/tex]
Whereas we can see a 2:4 mole ratio of potassium permanganate product to potassium hydroxide reactant with molar masses of 158.03 g/mol and 54.11 g/mol respectively. In such a way, by developing the following stoichiometric setup, we obtain the mass of KOH to start with:
[tex]m_{KOH}=200.0gKMnO_4*\frac{1molKMnO_4}{158.03gKMnO_4}*\frac{4molKOH}{2molKMnO_4} *\frac{56.11gKOH}{1molKOH}\\\\m_{KOH}= 142.0gKOH[/tex]
Best regards!