Answer:
![m_(O_2)=120gO_2](https://img.qammunity.org/2021/formulas/chemistry/college/xu4grwbz3ja271fc5jyg0j9689hjm153o6.png)
Step-by-step explanation:
Hello!
In this case, since the decomposition of potassium chlorate is:
![2KClO_3\rightarrow 2KCl+3O_2](https://img.qammunity.org/2021/formulas/chemistry/high-school/qolbsltq0t9lkz09cpqwx07wkp95wkhg2g.png)
We can see a 2:3 mole ratio between potassium chlorate and oxygen (molar mass 32.0 g/mol), thus, via stoichiometry, we compute the mass of oxygen that are produced by the decomposition of 2.50 moles of this reactant:
![m_(O_2)=2.50molKClO_3*(3molO_2)/(2molKClO_3) *(32.0gO_2)/(1molO_2)\\\\m_(O_2)=120gO_2](https://img.qammunity.org/2021/formulas/chemistry/college/hldbzaptlbp5nxri6p4prziwan9tmaur9e.png)
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