Question

A 106 mL solution of a dilute acid is added to 157 mL of a base solution in a coffee-cup calorimeter. The temperature of the solution increases from 22.94 oC to 27.29 oC. Assuming the mixture has the same specific heat (4.184J/goC) and density (1.00 g/cm3) as water, calculate the heat (in J) transferred to the surroundings, qsurr.

Answer 1

4897 J

Step-by-step explanation:

The heat transferred to the surroundings, q_surr, can be calculated using the equation:

q_surr = -q_rxn = -CmΔT

where C is the specific heat capacity of the mixture (assumed to be the same as water, 4.184 J/g°C), m is the mass of the mixture (which we can calculate using the density, assuming that the volumes are additive), and ΔT is the change in temperature (in Celsius).

First, let's calculate the mass of the mixture:

density of water = 1.00 g/cm^3

volume of mixture = volume of acid + volume of base = 106 mL + 157 mL = 263 mL = 0.263 L

mass of mixture = density of water x volume of mixture = 1.00 g/cm^3 x 0.263 L = 263 g

Next, let's calculate the change in temperature:

ΔT = final temperature - initial temperature = 27.29°C - 22.94°C = 4.35°C

Now we can calculate the heat transferred to the surroundings:

q_surr = -CmΔT

q_surr = -(4.184 J/g°C) x (263 g) x (4.35°C)

q_surr = -4897 J

Note that the negative sign indicates that heat is lost by the system to the surroundings. Therefore, the heat transferred to the surroundings, q_surr, is 4897 J.