Consider the reaction. how many grams of carbon should be burned in an excess of oxygen at stp to obtain 2.21 l of carbon dioxide? 1.18 g 2.21 g 4.12 g 4.34 g

You must burn 1.17 g C to obtain 2.21 L CO₂ at STP.

The balanced chemical equation is

C + O₂ → CO₂.

Step 1. Convert litres of CO₂ to moles of CO₂.

STP is 0 °C and 1 bar. At STP the volume of 1 mol of an ideal gas is 22.71 L.

Moles of CO₂ = 2.21 L CO₂ × (1 mol CO₂/22.71 L CO₂) = 0.097 31 mol CO₂

Step 2. Use the molar ratio of C:CO₂ to convert moles of CO₂ to moles of C

Moles of C = 0.097 31mol CO₂ × (1 mol C/1 mol CO₂) = 0.097 31mol C

Step 3. Use the molar mass of C to calculate the mass of C

Mass of C = 0.097 31mol C × (12.01 g C/1 mol C) = 1.17 g C

It looks as if you are using the old (pre-1982) definition of STP. That definition gives a value of 1.18 g C.

conduction is the transfer of thermal energy (heat in transfer) due to collisions between the molecules in the object. collisions between adjacent atoms and molecules transfer kinetic energy from the warmer to the cooler object. the objects must be in physical contact.