how many moles of O2 are needed to react with 4.00 moles of acetylene?

If you write the equation and balance it you will know.

how many moles of carbon dioxide are produced when 6.8 moles of acetylene reacts?

2C2H2 + 5O2 ==> 4CO2 + 2H2O

To determine how many moles of O2 are needed to react with 4.00 moles of acetylene, we need to examine the balanced chemical equation for the reaction between acetylene (C2H2) and oxygen (O2). The balanced equation is:

2C2H2 + 5O2 -> 4CO2 + 2H2O

From the balanced equation, we can see that for every 2 moles of acetylene (C2H2), we need 5 moles of oxygen (O2) to react completely.

Given that we have 4.00 moles of acetylene (C2H2), we can set up a ratio to determine the moles of oxygen (O2) needed:

(5 moles O2 / 2 moles C2H2) * 4.00 moles C2H2

Calculating this equation, we can find:

(5/2) * 4.00 = 10.00 moles O2

Therefore, 10.00 moles of O2 are needed to react with 4.00 moles of acetylene.