in 2CO(grams) + O2(grams) => 2CO2(grams), what is the ratio of moles of oxygen used to moles of CO2?

One to two

Jake is correct. I answered this question below.

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To determine the ratio of moles of oxygen used to moles of CO2 in the reaction 2CO + O2 -> 2CO2, we need to balance the equation first. Once balanced, the coefficients of the balanced equation will represent the mole ratio.

The balanced equation for the reaction is:
2CO + O2 -> 2CO2

From the equation, we can see that for every 1 mole of oxygen (O2), 2 moles of carbon dioxide (CO2) are formed. Therefore, the ratio of moles of oxygen used to moles of CO2 is 1:2.

In other words, for every mole of O2 used, 2 moles of CO2 are produced.