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 equation to use or something i can do the number crunching. i need the heat of the reaction in kj/mol. please help me
if im missing any info plz tell me ill get back to it asap. it was put in a styrofoam cupand the temperature of the solution was measured directly if that helps at all. i just need to know i guess whether or not im treating the data as a coffee cup calorimeter or doing something else with it. i can do the numbers i just need a push in the right direction.
calculate the molality of a solution of 3.76g NaOH in 85.0g H2O
To calculate the heat of the reaction in kJ/mol, we need to use the equation:
q = (m × C × ΔT) / n
Where:
- q is the heat transferred in Joules (J)
- m is the mass of the substance (in this case, the solution) in grams (g)
- C is the specific heat capacity of the solution in J/g·°C
- ΔT is the change in temperature in degrees Celsius (°C)
- n is the number of moles of the substance undergoing the reaction
First, let's determine the number of moles of HCl and MgCl2:
1. Calculate the number of moles of HCl:
- From the given mass of HCl (24.852 g) and molar mass of HCl (36.461 g/mol), use the formula: n = m / M
- nHCl = 24.852 g / 36.461 g/mol
2. Calculate the number of moles of MgCl2:
- From the given mass of MgCl2 (0.990 g) and molar mass of MgCl2 (95.211 g/mol), use the formula: n = m / M
- nMgCl2 = 0.990 g / 95.211 g/mol
Next, we need to determine the mass of the solution. To do this, subtract the individual masses of Mg and HCl from the total mass of the mixture:
Mass of solution = Total mass - (mass of HCl + mass of Mg)
Now that we have the mass of the solution, we can calculate the heat transferred using the formula mentioned above. However, we still need the specific heat capacity of the solution (C).
To obtain a value for C:
1. Determine the heat capacity of the calorimeter by multiplying the mass of the calorimeter (3.711 g) by its specific heat capacity (which you may need to look up or assume if not provided).
Now that you have the heat capacity of the calorimeter, you can subtract it from the total heat measured to get the heat of the reaction. Divide this value by the number of moles of MgCl2 to obtain the heat of the reaction per mole.
Remember to convert the final answer from Joules to kilojoules by dividing by 1000.
I hope this explanation helps you in performing the necessary calculations.