PREVNEXTSUBMITMenuResourcesGlossaryNotesClear and return to MenuSearch ResultsFilterSlide TextNotesSearch in:Check to includeSearch...TermsDefinitiondefinitionresourcessearchpauseplayreplaysubmitnextpreviousvolumespecific heat capacity imagine you are at the beach on a hot, sunny day, as you step on to the beach, in your bare feet what happens? how about if you step into the water? click on the beach and then the water to see how our character rosie reacts: specific heat capacity why was rosie happier in the water than on the sand? because the water felt much cooler on rosie's feet than the sand did. why would the water feel so much cooler when they've both been exposed to the sun all day? the reason is because it takes much more energy to increase the temperature of the water then it does to increase the temperature of the sand. this difference is due to the heat capacity of water vs. the heat capacity of sand. specific heat capacity as we just saw, some substances rise in temperature faster than others when exposed to the same amount of heat. the amount of energy that it takes to heat up 1 gram (g) of an object by 1 ºc is known as the specific heat capacity (c) of that object. specific heat capacity is given in units of: j/(g*ºc) and is represented in equations by the symbol: c, (where j = the amount of heat in joules) the greater the specific heat capacity, the longer it will take for an object to raise its temperature. in the case of the sand and the water, the water (4.18 j/(g*ºc)) has a much higher specific heat capacity than the sand (0.835 j/(g*ºc)) therefore the sand gets hotter much more quickly substances with high specific capacity also take much longer to cool off, this is why for example, a lake will remain warm into the fall as it still retains the heat it gained during the hot summer months calculating specific heat capacity to calculate the specific heat capacity of a substance, we use the equation: c = q / m x δt where: q = the amount of heat, in units of joules (j) m = the mass of the substance δt = the change in temperature (final temperature - initial temperature) lets try a practice problem. the temperature of 3.4 g of olive oil changes from 25 ºc to 89 ºc when 435 j of heat are added to it, what is the specific heat capacity of olive oil? try calculating this on your own and then follow along with the step by step after by clicking next next the temperature of 3.4 g of olive oil changes from 25 ºc to 89 ºc when 435 j of heat are added to it, what is the specific heat capacity of olive oil? c = q / m x δt calculating specific heat capacity step 1: list the variables c = ? m = 3.4 g q = 435 j t = (89º c - 25º c ) = 64 step 2: solve for the unknown c = ? m = 3.4 g q = 435 j t = (89º c - 25º c ) = 64 step 2: solve for the unknown c = 435 / (3.4 g x 64º c) c = 435 / (217.6 g x º c) c = 2.0 j / (g x º c) step 3:solution c = ? m = 3.4 g q = 435 j t = (89º c - 25º c ) = 64 step 2: solve for the unknown c = 435 / (3.4 g x 64º c) c = 435 / (217.6 g x º c) c = 2.0 j / (g x º c) step 3:solution the specific heat capacity (c) of olive oil is 2.0 j / (g x º c). in other words, it would take 2 j of energy to raise 1 gram of olive oil by 1 º c calorimetry we have described chemical processes as being either endothermic, where heat is absorbed by the system or exothermic, where heat is released from the system, the next step is actually measuring the amount of heat absorbed or released during a chemical reaction. to measure this, scientists have developed a technique known as calorimetry which uses a device known as a calorimeter to measure the precise values of heat absorbed or released in a chemical reaction or change of state in a calorimeter, the heat absorbed or released by a system is measured by a change in temperature. the image to the right represents a simple, constant pressure calorimeter called a coffee cup calorimeter styrofoam cups styrofoam lid stirrer thermometer water calorimetry calculations in calorimetry, the amount of heat absorbed or released by the system is represented by the symbol (q), which we have already seen in the calculation for specific heat, where q is in units of energy known as joules (j) to calculate q we use the following equation, which is simply a re-arranged version of the equation to calculate specific heat: q = m x c x δt where: q = amount of heat absorbed or released by the system m = mass of the substance you are measuring c = specific heat capacity of the substance you are measuring δt = the temperature change of the system (final temperature - initial temperature) calorimetry calculations when we calculate q we are trying to determine the heat released or absorbed by the system. in a calorimeter, the chemicals involved in the reaction are the system and the water in the calorimeter is the surroundings. we can use values of q to determine if a reaction or change of state is endothermic or exothermic if the value of q is negative this means that the system releases heat to the surroundings, the temperature of the water will increase, and the process is exothermic if the value of q is positive, the system has absorbed heat from the surroundings, the temperature of the water will fall and the process is endothermic q = positive = endothermic q = negative = exothermic lets try a couple of sample calorimetry problems styrofoam cups styrofoam lid stirrer thermometer liquid where reaction takes place coffee cup calorimeter a coffee cup calorimeter is comprised of: two styrofoam coffee cups, one sitting inside the other a solution where a chemical reaction can take place a thermometer to measure the change in temperature a stirrer to keep the solution uniform