Question

what is the value of delta ng if we consider the combustion of 1 mol of liquid ethanol if reactants and products are at 298K.
1) -1 2) -2 3) 1 4) 2​

Answer 1

Answer: 1) -1

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

The balanced equation for combustion of ethanol at 298 K is:

$C_2H_5OH(l)+3O_2(g)\rightarrow 2CO_2(g)+3H_2O(l)$

$\Delta ng$ = change in number of moles of gas particles = $n_{products}-n_{reactants}=2-3=-1$

Thus the value of delta ng if we consider the combustion of 1 mol of liquid ethanol if reactants and products are at 298K is -1.

Answer 2

the ans to this question is-1