Will an acyl chloride be attacked by water molecule to form carboxylic acid?
You need to lose a proton, then chloride becomes a better leaving group than hydroxide. In general, proton transfers are incredibly fast; in this scenario there is tons of water around to accept the proton, and the tetrahedral intermediate with a positively charged oxygen is fairly acidic anyway.



Mechanism from Clayden 2nd ed. (p 199).

In the absence of an external base (e.g. pyridine), water will act as the base itself here. Another way of approaching it is to note that hydrolysis of an acyl chloride will release one equivalent of HCl:

$$\ce{RCO\color{red}{Cl} + \color{red}{H}OH -&gt; RCOOH + \color{red}{HCl}}$$

so in the absence of a second base, you will necessarily have to produce $\ce{H3O+}$.