How many grams of zinc oxide can be produced from 7.3 moles of oxygen? * 2Zn + O2 → 2Zno
1188.13 g Zno
81.379 g Zno
7.3 g Zno
O 2g Zno

Mass = 1188.13 g

Explanation:

Given data:

Mass of ZnO produced = ?

Moles of oxygen = 7.3 mol

Solution:

Chemical equation:

2Zn + O₂       →      2ZnO

Now we will compare the moles oxygen and and ZnO.

               O₂          ;        ZnO

                1            :           2

              7.3          :           2/1×7.3 = 14.6 mol

Mass of ZnO:

Mass = number of moles × molar mass

Mass = 14.6 mol × 81.38 g/mol

Mass = 1188.13 g

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.