<u>Answer:</u> The molarity of citric acid that is commercially available lemon juice is 0.416 M
<u>Explanation:</u>
To calculate the concentration of acid, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is NaOH.
We are given:

Putting values in above equation, we get:

Hence, the molarity of citric acid that is commercially available lemon juice is 0.416 M
equation Fe3O4=Fe+CO2 is an impossible reaction
Through hemoglobin transport in blood, material exchange is carried out on the alveolar membrane.
From,
RAM=element×its relative abudance/total abudance
=((107×13)+(12×109))/25
The answer is=107.96
Hi,
Two sodium atoms are needed to create an ionic bond with sulfur.