Question

Aqueous hydrochloric acid will react with solid sodium hydroxide to produce aqueous sodium chloride and liquid water . Suppose 30.3 g of hydrochloric acid is mixed with 25. g of sodium hydroxide. Calculate the minimum mass of hydrochloric acid that could be left over by the chemical reaction. Be sure your answer has the correct number of significant digits.

Answer 1

Answer:

$m_{HCl}^{leftover}=7.50g$

Explanation:

Hello.

In this case, since the undergoing chemical reaction is:

$HCl+NaOH\rightarrow NaCl+H_2O$

In order to identify the limiting reactant, we compute the available moles of sodium hydroxide (molar mass = 40 g/mol) and the moles of hydrochloric acid consumed by those moles via their 1:1 mole ratio considering the chemical reaction:

$n_{HCl}=25.0gNaOH*\frac{1molNaOH}{40gNaOH} *\frac{1molHCl}{1molNaOH} =0.625molHCl$

Next, since the molar mass of hydrochloric acid is 36.46 g/mol, we compute the mass of that reactant that is actually consumed:

$m_{HCl}=0.625molHCl*\frac{36.46gHCl}{1molHCl}=22.8gHCl$

In such a way, the leftover of HCl is:

$m_{HCl}^{leftover}=30.3g-22.8g\\\\m_{HCl}^{leftover}=7.50g$

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