For each of the following acid-base reactions,
calculate the mass (in grams) of each acid necessary
to completely react with and neutralize 3.65 g of the
base.
Part A
HCl(aq) + NaOH(aq) → H2O(l) + NaCl(aq)

Part B
2 HNO3(aq) + Ca(OH)2(aq)
2 H2O(1) + C


Respuesta :

Answer: A. 3.28 g of HCl

B. 6.30 g of [tex]HNO_3[/tex]

Explanation:

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]    

[tex]\text{Moles of} NaOH=\frac{3.65g}{40g/mol}=0.09moles[/tex]

[tex]\text{Moles of} Ca(OH)_2=\frac{3.65g}{74g/mol}=0.05moles[/tex]

a) [tex]HCl(aq)+NaOH(aq)\rightarrow H_2O(l)+NaCl(aq)[/tex]  

According to stoichiometry :

1 mole of [tex]NaOH[/tex] require = 1 mole of [tex]HCl[/tex]

Thus 0.09 moles of [tex]NaOH[/tex] will require=[tex]\frac{1}{1}\times 0.09=0.09moles[/tex]  of [tex]HCl[/tex]

Mass of [tex]HCl=moles\times {\text {Molar mass}}=0.09moles\times 36.5g/mol=3.28g[/tex]

b) [tex]2HNO_3(aq)+Ca(OH)_2(aq)\rightarrow 2H_2O(l)+Ca(NO_3)_2(aq)[/tex]  

According to stoichiometry :

1 mole of [tex]Ca(OH)_2[/tex] require = 2 moles of [tex]HNO_3[/tex]

Thus 0.05 moles of [tex]Ca(OH)_2[/tex] will require=[tex]\frac{2}{1}\times 0.05=0.1moles[/tex]  of [tex]HNO_3[/tex]

Mass of [tex]HNO_3=moles\times {\text {Molar mass}}=0.1moles\times 63g/mol=6.3g[/tex]