We did a thermochemistry lab the other day in my Chem 151 class and I'm a little confused on some of the calculations. Here's what we did:
Mixed 50.0mL of 1.0M NaOH with 50.0mL of 1.0M HCl in calorimeter. Observed change in temp was +6.7°C.
To calculate the heat gained by the solution, we were giving this formula: (DeltaT)(mass)(specific heat H2O) = (6.7 K)(mass)(4.18 J/g-K)
I confused as to what to put for the mass. Since we are calculating the heat gained by the solution, do I plug in the entire mass or just the mass of the NaOH or HCl?
Also to calculate the mass, it says in the lab that the density of the soltuions used is appoximately 1.00g/mL, so I can convert the volume into mass by using the given density, right?
Mixed 50.0mL of 1.0M NaOH with 50.0mL of 1.0M HCl in calorimeter. Observed change in temp was +6.7°C.
To calculate the heat gained by the solution, we were giving this formula: (DeltaT)(mass)(specific heat H2O) = (6.7 K)(mass)(4.18 J/g-K)
I confused as to what to put for the mass. Since we are calculating the heat gained by the solution, do I plug in the entire mass or just the mass of the NaOH or HCl?
Also to calculate the mass, it says in the lab that the density of the soltuions used is appoximately 1.00g/mL, so I can convert the volume into mass by using the given density, right?
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You plug in the total mass of water in the two solutions. In both the naoh and hcl solutions there is 50 ml so the total is 100ml. Don't worry about the mass of naoh and hcl because you're using the change in temp of the water to find the heat released. As you said the density of water is 1.00g per mL. So there's a total of 100 grams