Answer: The new volume of the air in the syringe is 7.3 mL.
Explanation:
Given:
= 2.0 mL,
= 1.02 atm, 
= ?,
= 1.27 atm, 
Formula used to calculate the new volume in syringe is as follows.

Substitute the values into above formula as follows.

Thus, we can conclude that the new volume of the air in the syringe is 7.3 mL.
A I think I could be wrong I’m not good at this
Answer:
0.00369 moles of HCl react with carbonate.
Explanation:
Number of moles of HCl present initially =
moles = 0.00600 moles
Neutralization reaction (back titration): 
According to above equation, 1 mol of NaOH reacts with 1 mol of 1 mol of HCl.
So, excess number of moles of HCl present = number of NaOH added for back titration =
moles = 0.00231 moles
So, mole of HCl reacts with carbonate = (Number of moles of HCl present initially) - (excess number of moles of HCl present) = (0.00600 - 0.00231) moles = 0.00369 moles
Hence, 0.00369 moles of HCl react with carbonate.