Mole-mass conversions how many moles in 28.o grams of oxygen? what is the mass of 5.0 moles of iron? find the number of moles of argon in 452 g of argon. find the grams in 16.5 mol of hydrogen.

1.) 28.0 grams of oxygen
28 grams (1 mole/16 grams per mole)=1.75 moles oxygen
2.)5.0 moles of Iron
5 moles(55.845 grams/1 mole)=279.225 grams Iron
3.) 452 grams Argon
452 grams(1 mole/39.948 grams)=11.315 moles Argon
4.) 16.5 moles Hydrogen
16.5 moles(1.01 grams/1 mole)=16.665 grams Hydrogen

Answer:

a. energy is absorbed in the reaction.

explanation:

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.

What are the choices?