Wednesday
April 16, 2014

Homework Help: Chemistry

Posted by Kara on Sunday, March 27, 2011 at 11:45pm.

In the classroom, we reacted
Mg(s) + 2HCl -> MgCl2(aq) + H2 (g)
(0.31 g of Mg(s), and 99.46 g of HCl)
Initial temp. = 22.5 celsius, max. temp. 36.0 celsius

and

MgO(s) + 2HCl -> MgCl2(aq) + H2(g)
(1.00 g of MgO(s) and 97.71 g of HCl)
Initial temp. 22.0 celsius, max. temp. 28.5 celsius.

Please note that the temperatures were crudely taken, so a wide range of experimental error is likely.

When calculating the deltaH for the first equation, this is what I got

Q=mcDeltaT
Q=(99.46)(4.18)(13.5)
Q=5612.5 J
Q=5.6 kJ

and the second reaction;

Q=mcDeltaT
Q=(97.71)(4.18)(6.5)
Q=2654 J
Q=2.7 kJ

My question is, how do those numbers make any sense? Or am I just confused as to what those numbers represent? Thanks in advance!

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

Chemistry - Mg(s) + 2HCl(aq) --> MgCl2(aq) + H2(g) If 1.0g of Mg is reacted ...
Chemistry - Mg(s) + 2 HCl(aq) --> MgCl2(aq) + H2 (g) DeltaH= -4.6x10^2 kJ How...
Ap chem question 2 related to the first question - Calculate the volume of gas ...
Chemistry - How many mole of H2 will be produced if 0.500 grams of magnesium is ...
Chemistry - If Chelcy and Allyson reacted 2.55 grams of Mg with excess ...
chemistry - Over an interval of 1second (s) the mass of Mg(s), in the reaction ...
Chemistry - Can someone tell me if I have this correct, I am leaving something ...
chemistry - In the reaction Mg (s) + 2HCl (aq) H2 (g) + MgCl2 (aq), how many ...
Chemistry - Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g) If 2.00 g of Mg reacts ...
chemistry - consider the following reaction: Mg(s)+ 2HCl(aq) --> MgCl2 (aq)+...

Search
Members