When x grams of carbon are heated with y grams of oxygen in a closed vessel, Why no solid residue is left behind?

When x gm carbon is burnt with y gm oxygen in a closed vessel, no residue is left behind. Which of the following statement is correct regarding the relative amounts of oxygen and carbon?

A mixture of 2 mol of carbon monoxide and 1 mol of oxygen in a closed vessel is ignited to get carbon dioxide , then

A mixture of 2 mol of carbon monoxide and 1 mol of oxygen in a closed vessel is ignited to get carbon dioxide , then

A gaseous mixture contains 160 grams of neon and 64 grams of oxygen in 82.1 litre vessel at 27^@C , then the partical pressure of Neon may be - atm

After heating washing soda, the colour of residue left behind would be

When NaCl_3 is heated in a closed vessel, oxygen is liberated and NaNO_2 is left behind. At equilibrium:

When NaNO_3 is heated in a closed vessel, oxygen is liberated and NaNO_2 is left behind. At equilibrium