Explain why is it possible to use the value 4.184 j/g C for the heat capacity of the various solutions in this experiment (HCL HNO3 H2SO4 CH3COOH H3PO4 HCOOH (COOH)2)
The value 4.184 J/g °C is often used as an approximation for the heat capacity of solutions in certain experiments. This value corresponds to the heat capacity of water, which is commonly used as a reference substance due to its consistent behavior and availability of data.
When measuring the heat capacity of a solution, it is important to consider the specific heat capacity of the solute and the solvent. In this case, since the solutions mentioned are aqueous solutions, the solute is the acidic compound (e.g., HCl, HNO3, H2SO4, etc.), and the solvent is water (H2O).
To calculate the heat capacity of these solutions, one approach is to use the weighted average of the heat capacities of the components. This means taking into account the relative proportions of the solute and solvent in the solution. However, if the concentration of the acid is relatively low (often the case in typical experiments), the effect of the solute on the overall heat capacity is minor compared to the heat capacity of water.
Since the heat capacity of water is around 4.184 J/g °C, it is often used as an approximation for the heat capacity of these acid solutions. This approximation assumes that the contribution of the solute to the overall heat capacity is negligible. While this may not be completely accurate, it provides a reasonable estimation for practical purposes in many experimental scenarios.
It is worth noting that if more precise results are required, the heat capacity of solutions can be determined experimentally using calorimetry techniques or by referring to more specific data available in scientific literature for particular acid solutions at different concentrations and temperatures.