Question

Question 21 (1 point) What is As for the reaction 2CH2OH(g) + 302(g) →2C02(g) + 4H20(8): 88.0J/K +8801/ 0-42.31/K +4231/K Net Page 21 of 22 Delen SIALAI Dockey

Answer 1

What is $\Delta$S^o for the reaction 2CH₃OH_(g) + 3O_2(g) ------> 2CO_2(g) + 4H₂O_(g)

ans) 88.0 J/K

Explanation

What is entropy?

The randomness and the molecule disorder rely on the available different arrangements in a given reaction or a system is characterised by a thermodynamic quantity called entropy, Which is denoted by the letter S.

Here the question is about $\Delta$S^o which is called Standard Entropy Change

Standard Entropy Change

The difference between the total no.of standard product entropies and the total no.of standard reactant entropies will give the value for Standard Entropy Change.

$\Delta$S^o_rxn is the symbol for Standard Entropy Change. The SI unit will be J/mol.K.

Formula for the calculating the Standard Entropy Change

$\Delta$S^o_rxn = $\sum$n.S^o (products) -  $\sum$n.S^o (reactants)

S^o (reactants) = Standard entropy value for the reactants

S^o (products) = Standard entropy value for the products

n = significant for the entropy of each compound should be multiplied by its coefficients in the balanced equation.

According to the equation 2CH₃OH_(g) + 3O_2(g) ------> 2CO_2(g) + 4H₂O_(g)

Standard entropy value for CH₃OH_(g) =   239.7 J/mol.K

Standard entropy value for O_2(g) =   205 J/mol.K

Standard entropy value for CO_2(g) =   213.67 J/mol.K

Standard entropy value for H₂O_(g) =   188.7 J/mol.K

The formula for calculating the Standard Change in entropy for this specific reaction is

$\Delta$S^o_rxn = [2.S^o(CO₂ (g)) + 4.S^o (H₂O) (g))] - 2.S^o(CH₃OH (g)) + 3.S^o (O₂) (g))]

Applying these values in the formula

$\Delta$S^o_rxn = [ 2(213.67 J / mol.K) + 4(188.7 J/mol.K)] - [ 2 (239.7 J / mol.K) + 3(205 J / mol.K)]

= [427.34 J /mol.K + 754.8 J / mol.K] - [479.4 J / mol.K + 615 J / mol.K]

= 1182.14 J /mol.K - 1094.4 J / mol.K

= 87.74 J / mol.K

By taking as the whole number for the answer will be

$\Delta$S^o for the reaction 2CH₃OH_(g) + 3O_2(g) ------> 2CO_2(g) + 4H₂O_{(g) =}   88.0 J /mol.K