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Fe(s) + 2HCl(aq) --> FeCl2(aq) + H2(g)

When a student adds 30.0 mL of 1.00 M HCl to 0.56 g of powdered Fe, a reaction occurs according to the equation above. When the reaction is complete at 273 K and 1.0 atm, which of the following is true?

A) HCl is in excess, and 0.100 mol of HCl remains unreacted.

D) 0.22 L of H2 has been produced.

The correct answer is D. I can't figure out why A is wrong.

Respuesta :

Answer:

In the option(A) moles of HCl left are 0.100 moles which is wrong, making the option incorrect.

Explanation:

[tex]Fe(s) + 2HCl(aq)\rightarrow  FeCl_2(aq) + H_2(g) [/tex]

Moles of HCl = n

Molarity of HCl = 1.0M

Volume of HCl solution = 30.0 mL = 0.030 L (1 mL = 0.001L)

[tex]Moles=Molarity\times Volume (L)[/tex]

[tex]n=1.0M\times 0.030 L=0.030 mol[/tex]

Moles of Fe = [tex]\frac{0.56 g}{56 g/mol}=0.01 mol[/tex]

According to recation , 1mol of Fe reacts with 2 mol HCl. Then 0.01 mole of Fe will recat with :

[tex]\frac{2}{1}\times 0.01 mol= 0.02 mol[/tex] of HCl

This means that HCl uis in excess , hence excessive reagent.

Moles of HCl left unreacted :

= 0.030 mol - 0.020 mol = 0.010 mol

But in the option moles of HCl left are 0.100 moles which is wrong, making the option incorrect.

Option A states that 0.1 moles of HCl remain unreacted. This proves that option A is incorrect. The volume of hydrogen gas produced is 0.22 L. Thus option D is correct.

From the given reaction, 1 mole of Fe and 2 moles of HCl reacts to form 1 mole ferric chloride and 1-mole hydrogen gas.

The number of moles of HCl in 30 ml 1 M solution are:

Moles = molarity [tex]\times[/tex] volume (L)

Moles of HCl = 1 [tex]\times[/tex] 0.03

Moles of HCl = 0.030 moles.

The moles of 0.56 grams Fe powder are :

Moles = [tex]\rm \dfrac{weight}{molecular\;weight}[/tex]

Moles of Fe = [tex]\rm \dfrac{0.56}{56}[/tex] moles

Moles of Fe = 0.01 moles

  • For the reaction of 1 mole of Fe, 2 moles of HCL is required.

For the reaction of 0.01 moles of Fe, moles of HCl required = 0.01 [tex]\times[/tex] 2

Moles of HCL reacted = 0.02 moles

Total moles of HCL = 0.03 moles

Moles of HCl unreacted = 0.03 - 0.02

Moles of HCl unreacted = 0.01 moles

Option A states that 0.1 moles of HCl remain unreacted. This proves that option A is incorrect.

  • 1 mole of Fe form 1 mole of Hydrogen gas.

0.01 moles of Fe form, 0.01 mole of Hydrogen gas.

From the ideal gas equation:

PV = nRT

1 [tex]\times[/tex] Volume = 0.01 [tex]\times[/tex] 0.0821 [tex]\times[/tex] 273

Volume of Hydrogen gas = 0.22 L.

The volume of hydrogen gas produced is 0.22 L. Thus option D is correct.

For more information about the chemical reaction, refer to the link:

https://brainly.com/question/1689737

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