Are My Chemical Reaction Equations Correct?

[MacLaddy]

Homework Statement

I have a couple of problems here that are all part of one homework problem. A,B,C, and D. I have completed what I believe are the correct answers, but I really don't know for sure. This is an online chemistry class, and it really is not very good. I've watched about 3 hours of Khan Academy videos, and 1+ hours of Brightstorm, plus all my required reading- and I just seem to be missing something.

Anyway, if someone could just look these over I would appreciate it.


Give the chemical formula equation for the following reactions.

(A.) Potassium metal reacting with water to produce potassium hydroxide and hydrogen gas.

(B.) The bicarbonate, $HCO_3$ ion reacting with the $H^+$ ion to produce water and carbon dioxide.

(C.) Copper metal reacting with silver nitrate solution to make silver metal and copper(II) nitrate.

(D.) Iron metal reacting with oxygen gas to make iron(III) oxide.

Homework Equations

The Attempt at a Solution

(A.)
$K + H_2O \rightarrow KOH + H^2$

=$2K + 2H_2O \rightarrow 2KOH + H_2$

(B.)
=$HCO_3^- + H^+ \rightarrow H_2O + CO_2$

(C.)
$Cu + AgNO_3 \rightarrow Ag + Cu(NO_3)_2$ Substitute $X=NO_3$
$Cu + AgX \rightarrow Ag + CuX_2$
$Cu + 2AgX \rightarrow 2Ag + CuX_2$

=$Cu + 2AgNO_3 \rightarrow 2Ag + Cu(NO_3)_2$

(D.)
$Fe + O_2 \rightarrow Fe_2O_3$
$2Fe + 1.5O_2 \rightarrow Fe_2O_3$
$2(2Fe + 1.5O_2 \rightarrow Fe_2O_3$

=$4Fe + 3O_2 \rightarrow 2Fe_2O_3$

Any advice, or even a swift boot in the right direction, would be greatly appreciated.

Thanks,
Mac

 

[Borek]

In general you got it right. The only thing I would modify would be to add (s), (aq) and (g) to reagents to show their state, so for example your second reaction would look like

Cu(s) + 2AgNO₃(aq) -> 2Ag(s) + Cu(NO₃)₂(aq)

 

[MacLaddy]

Ah, thanks Borek. I forgot about adding the physical state symbols. My teacher does require that.

Just curious, looking at these after a nights sleep, does the second equation $HCO_3^- + H^+ \rightarrow H_2O + CO_2,$ need to instead be this $HCO_3^- + H_2^+ \rightarrow H_2O + CO_2$?

It seems to me that Hydrogen can not stand alone. (even though that's how it's worded in the book)

Thanks again.

 

[Borek]

No, it is H⁺, or H₃O⁺.

See http://en.wikipedia.org/wiki/Hydronium

 

[DeeNos]

Hello Mac,

Thank you for sharing your homework problems with me. It's great that you have taken the time to do some extra research and watch videos to understand the concepts better. Here are my thoughts on your answers:

(A.) Your chemical formula equation is correct, but I would recommend writing the hydrogen gas as H2 instead of H^2.

(B.) Your equation is also correct, but I would suggest writing the bicarbonate ion as HCO3^- instead of just HCO_3.

(C.) Your equation is correct, but instead of using X as a substitute for nitrate, you can write it as NO3^- to make it clearer.

(D.) Your equation is correct, but I would suggest writing the iron oxide as Fe2O3 instead of Fe_2O_3.

Overall, your equations are correct and your understanding of chemical formulas and reactions seems to be on the right track. Keep up the good work and don't hesitate to ask for help or clarification when needed. Good luck with your studies!