posted by .

So I am writing a lab report and Im stuck with calculating the enthalpy change of combustion of the following reaction:
Mg+2HCl--> MgCl2+H2 .I am given the mass of Mg which is 5g and the concentration of HCl which is 2M and the volume of HCl which is 50 cm^3.I found the limiting reactant which was HCl and i have to measure the ÄÇ of combustion..I know that HE(HEAT ENERGY)=m x c x ÄT and the change in temperature is 10 degrees celsius. I also know that in order to find ÄH we divide HE with n which is the number of moles of the limiting reactant..can anyone please help me find the ÄH?i DON'T know whose mass to use, i know i have to use the heat capacity of water..and i don't know whether i have to convert temperature into Kelvin measurement.

  • Chemistry -

    Frankly, I don't know how you are to calculate heat of combustion when you didn't combust Mg but reacted it with HCl instead.
    You measured the T difference of the water; therefore, find the q from mc*delta T by using the mass of water (50 cc = 50g if the density is 1.00 g/cc) and the specific heat of water.

  • Chemistry -

    we were asked to find the enthalpy change because it is an exothermic reaction. Don't i have to convert cm^3 into dm^3 in the equation?when i divide the Heat energy with the number of moles in order to get enthalpy change do i put the moles of the limiting reagent?

  • Chemistry -

    You want the mass of the water and the volume of the water is 50 cc. Since the density is 1.00 g/cc, the mass is 50 g. You CAN convert cc to dm^3 if you want to use a different value for density in g/dm^3. After finding q, then delta H rxn = q/n for the limiting reagent which gives J/mol for the unit.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Chemistry

    g+ 2HCl-->MgCl2+H2 The mass of the HCl is 24.852 g mass of the Mg is .990 g and the mass of the calorimeter is 3.711 g. the change in temperature of the solution was +19 degrees celcius. itd be great if i could just get a basic …
  2. Chemistry

    I'm trying to calculate the enthalpy of the reaction Mg(s) + 2HCl(aq) -> MgCl2(aq) + H2 (g) however I cannot find the enthalpy of the compound MgCl2 (aq) and I cannot calculate the total enthalpy without it
  3. chemistry

    in the equation mg+2hcl-->mgcl2+h2, what mass of the hcl is consumed by the reaction of 2.50 mol of magnesium
  4. Chemistry

    It's a molar heat reaction lab. 0.07g Mg Mg+2HCl->MgCl2+H2 What is the actual value for the heat of reaction based on the enthalpy's of formation?
  5. Chemistry

    Help with lab report Need Help finishing my lab report.KNOWN VALUES ARE V OF HCL=50ML,M=2.188.V OF NAOH=55.3ML,M=2.088.INTIAL TEMP FOR HCL=22.5C,NAOH IS 23C.this is for part A: Mass of final NACL solution assuming that the density …
  6. Chemisty

    Calculate the standard enthalpy change for the following reaction at 25 °C. MgCl2(s)+H2O(l)-->MgO(s)+2HCl
  7. Chemistry

    Calculate the standard enthalpy change for the following reaction at 25 °C. MgCl2(s) + H2o(l) ---> MgO(s) + 2HCl(g)
  8. Chemistry

    Calculate the enthalpy change of formation for the following reactions using Hess's law, and the enthalpies of formation given in Figure 4: b) MgO +2HCl --> MgCl2 +H2O c)NaOH+ HCl -->NaCl +H20 Figure4: the given enthalpies of …
  9. Chemistry

    The combustion reaction of Mg +1/2 O2-->MgO produces a very bright white flame and high heat. Verify that the following reactions produce the same overall reaction: a) MgO+2HCl-->MgCl2+H2O b) Mg+2HCl-->MgCl2+H2 c) H2+1/2O2-->H2O …
  10. Chemistry (molarity) (sorta an emergency)

    I'm doing a titration lab and writing a lab report where I'm sort of stuck on how exactly to find the concentration of HCl. These are the following info I have from the lab, Equation: HCl(aq)+NaOH(aq)-> H2O(l)+NaCl(aq) -Calculated …

More Similar Questions