To calculate the heat capacity, we can use the formula:q = mcTwhere q is the heat energy in Joules , m is the mass of the substance in grams , c is the specific heat capacity in J/gK , and T is the change in temperature in Kelvin or Celsius, since the difference is the same .We are given the mass m = 50.0 g , the heat energy q = 167 J , and the change in temperature T = 5.00 C . We need to find the specific heat capacity c and then calculate the heat capacity.First, let's rearrange the formula to solve for c:c = q / mT Now, plug in the given values:c = 167 J / 50.0 g 5.00 C = 167 J / 250 gC = 0.668 J/gCNow that we have the specific heat capacity, we can calculate the heat capacity. The heat capacity is the product of the mass and the specific heat capacity:Heat capacity = m c = 50.0 g 0.668 J/gC = 33.4 J/CSo, the heat capacity of the 50.0 g sample of the unknown substance is 33.4 J/C.