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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: darkwizard267787 on September 22, 2022, 12:01:53 PM

Title: Can someone help with this question?
Post by: darkwizard267787 on September 22, 2022, 12:01:53 PM: A container contains a solution of HCl_(aq)0.5M, someone added 12gr of Fe_(s). The chemical reaction formed FeCl_3(aq) and H_2(g).
1. What is the volume of acid that reacted?
2. What is the concentration of the cations and the concentration of the anions in the solution (use the volume from the first question)?
Title: Re: Can someone help with this question?
Post by: Corribus on September 22, 2022, 12:41:18 PM: The forum rules require you to show your work to receive help.
Title: Re: Can someone help with this question?
Post by: Babcock_Hall on September 22, 2022, 05:37:38 PM: In general it is a good idea to write a balanced equation.
Title: Re: Can someone help with this question?
Post by: darkwizard267787 on September 23, 2022, 04:52:29 AM: Hi, thank you for your response

This is what I have done
6HCl_(aq)+2Fe_(s) :rarrow: 3H_2(g)+2FeCl_3(aq)
0.5M=0.21mol/X
x= 0.42L
FeCl_3(aq) :rarrow:^H₂OFe³⁺+3Cl^-

I just don't understand how to solve the second question
Title: Re: Can someone help with this question?
Post by: Borek on September 23, 2022, 07:17:46 AM: How many moles of Fe³⁺? In what volume? What is the concentration of Fe³⁺ then?

Same about Cl^-.
Title: Re: Can someone help with this question?
Post by: Enthalpy on September 26, 2022, 05:40:29 AM: Can the question be answered? I feel it lacks something like "both reactants are completely consumed".
Title: Re: Can someone help with this question?
Post by: Aldebaran on September 26, 2022, 11:45:16 AM: Yes it can be answered but I don’t think the question is written very well.
Title: Re: Can someone help with this question?
Post by: Babcock_Hall on September 27, 2022, 10:13:47 AM: Quote from: Enthalpy on September 26, 2022, 05:40:29 AM
Can the question be answered? I feel it lacks something like "both reactants are completely consumed".
I think that when the question does not specify, it is fine to assume a complete reaction.
Title: Re: Can someone help with this question?
Post by: billnotgatez on September 27, 2022, 10:24:43 PM: @Babcock_Hall Do you think that making that assumption is a fair requirement for a High School student?

Quote from: Babcock_Hall on September 27, 2022, 10:13:47 AM
Quote from: Enthalpy on September 26, 2022, 05:40:29 AM
Can the question be answered? I feel it lacks something like "both reactants are completely consumed".
I think that when the question does not specify, it is fine to assume a complete reaction.
Title: Re: Can someone help with this question?
Post by: Borek on September 28, 2022, 02:44:14 AM: Quote from: billnotgatez on September 27, 2022, 10:24:43 PM
@Babcock_Hall Do you think that making that assumption is a fair requirement for a High School student?

It is a common assumption, it would be quite surprising to see a problem that doesn't use it.

Question is a bit strange, as it is not "volume of the acid that reacts", but "amount of acid that reacts", other than that it is just a kind of limiting reagent problem. Typical HS stuff.
Title: Re: Can someone help with this question?
Post by: Babcock_Hall on September 28, 2022, 08:38:10 AM: Quote from: billnotgatez on September 27, 2022, 10:24:43 PM
@Babcock_Hall Do you think that making that assumption is a fair requirement for a High School student?

Quote from: Babcock_Hall on September 27, 2022, 10:13:47 AM
Quote from: Enthalpy on September 26, 2022, 05:40:29 AM
Can the question be answered? I feel it lacks something like "both reactants are completely consumed".
I think that when the question does not specify, it is fine to assume a complete reaction.
I think that the question would be improved by stating this outright, but I don't think that this assumption is beyond the means of a high school student.
Title: Re: Can someone help with this question?
Post by: Corribus on September 28, 2022, 09:33:35 AM: I think questions in introductory chemistry courses always do well to spell out what assumptions students should be making to solve them - even if those assumptions are rather obvious or routine. Doing so serves as a good reminder to students that assumptions are always being made and sometimes we don't even realize it. Being aware of what assumptions you are making when forming a conclusion from experimental data is the foundation of sound science.