If 146.5 g of chromium (iii) chlorate decomposes what mass of oxygen can be produced

The Equation for this reaction is as follow,
                                2 Cr(ClO₃)₃    →    2 CrCl₃  +  9 O₂

According to eq,

       604.68 g (2mole) of Cr(ClO₃)₃ produces  =  288 g (9 moles) of O₂
So,
                  146.5 g of Cr(ClO₃)₃ will produce  =  X g of O₂

Solving for X,
                              X  = (146.5 g × 288 g) ÷ 604.68 g

                              X  =  69.77 g of O₂

That is a lot of moles that you have

For lesson: cameras, plant presses, newspaper, paper towels, clip boards, pencils, calculators, field guides, metric measuring tapes, paper, transect squares, colored pencils, ph meters, light meters, computers, etc.for extension: baggies for soil samples collecting, distilled water, hand shovels, beakers, boiled rice, microscopes, well microscope slides or regular microscope slides with cover slips