What heat means in thermodynamics, and how we can calculate heat using the heat capacity.
Log in Tu Huynh 8 years agoPosted 8 years ago. Direct link to Tu Huynh's post “For I know that Kelvin is...” For I know that Kelvin is always positive, but why in the example, why Kevin degree is negative? • (6 votes) C Hart 8 years agoPosted 8 years ago. Direct link to C Hart's post “Couple things:1. Be car...” Couple things: (51 votes) Nanananananananana 9 years agoPosted 9 years ago. Direct link to Nanananananananana's post “Why is it in my book it i...” Why is it in my book it is indicated that q = C x change in T, where C is heat capacity (J/C). C is then equal to (m x s x change in T)hot + (m x s x change in T)cold/-change in T, where s is the specific heat capacity (J/gC). Can you please explain to me? I'm quite confused. • (4 votes) Ernest Zinck 9 years agoPosted 9 years ago. Direct link to Ernest Zinck's post “q = CΔT and q = msΔT, so ...” q = CΔT and q = msΔT, so C = ms. You often set up your calculations like this: (17 votes) danishsa314 9 years agoPosted 9 years ago. Direct link to danishsa314's post “i did not understand how ...” i did not understand how chemists use the melting point to identify the purity of a substance • (5 votes) Rohan Bassi 9 years agoPosted 9 years ago. Direct link to Rohan Bassi's post “Chemists can heat up subs...” Chemists can heat up substances to the point when they start to melt. At this temperature, the chemists can compare this value to a table of standard results from a data table/source/reference. The standard results are the true results for that particular substance. However, when a substance has an experimental melting point significantly higher than the standard data book value, then we know there must be impurities present. Impurities may have a higher melting point than the substance we're interested in, so the overall melting point for the impure substance is higher than expected. (11 votes) Fatima Naz 7 years agoPosted 7 years ago. Direct link to Fatima Naz's post “Why do kelvins don't have...” Why do kelvins don't have degree? • (3 votes) Abdülrezzak Bostani 7 years agoPosted 7 years ago. Direct link to Abdülrezzak Bostani's post “In general, 'degrees' are...” In general, 'degrees' are found in units which are mainly arbitrary. Fahrenheit and Celsius are meant to be convenient instead of absolute. The same goes for angle degrees, since that also divides the circle into 360 degrees arbitrarily. Like, there is no 'degrees' in radians, which is the 'natural' way of measuring angles. The kelvin is the SI base unit of temperature. it is the absolute temperature scale. By absolute we mean that the zero on the Kelvin scale, denoted by 0 K, is the lowest temperature that can be attained theoretically. On the other hand, 0 F and 0 C are based on the behavior of an arbitrarily chosen substance. For Kelvin. Temperature is defined in terms of the average energy of particles in a system, and Kelvin is directly proportional to that -- the zero in the Kelvin scale corresponds to absolute zero, and not any arbitrary temperature, and Kelvin is the 'natural' unit to measure temperature. (13 votes) Suraj Singh 8 years agoPosted 8 years ago. Direct link to Suraj Singh's post “Why the Zeroth Law of the...” Why the Zeroth Law of thermodynamics is called so,is it the most basic law? • (5 votes) Mohd. Nomaan 8 years agoPosted 8 years ago. Direct link to Mohd. Nomaan's post “zeroth law was discovered...” zeroth law was discovered after the first law and other thermodynamic laws (9 votes) aricohens13 7 years agoPosted 7 years ago. Direct link to aricohens13's post “Underneath the picture of...” Underneath the picture of the ice cubes, the caption reads, "As ice melts, heat is transferred from the water to the surroundings." Shouldn't it read, "As ice melts, heat is transferred from the surroundings to the ice" or something similar? • (5 votes) skofljica 7 years agoPosted 7 years ago. Direct link to skofljica's post “yeah, i would say you're ...” yeah, i would say you're right. heat is always spontaneously transferred from (object of) higher to lower temperature. (4 votes) Kay Johnson 8 years agoPosted 8 years ago. Direct link to Kay Johnson's post “Why is it often not possi...” Why is it often not possible to directly measure the heat energy change of the reactants and products? • (3 votes) jd.agg6961 6 years agoPosted 6 years ago. Direct link to jd.agg6961's post “Can two bodies of differe...” Can two bodies of different temperatures in thermal contact do not necessarily attain a mean temperature. Explain the reason behind this (1 vote) ac4444122 6 years agoPosted 6 years ago. Direct link to ac4444122's post “Can somebody give me an e...” Can somebody give me an example that shows the difference between heat and temperature? • (1 vote) Lucas De Oliveira 6 years agoPosted 6 years ago. Direct link to Lucas De Oliveira's post “A thermometer shows the t...” A thermometer shows the temperature because it measures (compare) the degree of agitation of its molecules in relation to the degree of agitation of the molecules of the environment, but this is only possible because you transfer heat to the thermometer. This is because 2 bodys at different temperatures tend to get in the thermal balance between them with the one that is hot by giving energy to the coldest in the form of heat, so on a cold day you wear a jacket not to heat yourself but to reduce the loss of thermal energy to the environment in the form of heat. (4 votes) Keitumetse Madiga a year agoPosted a year ago. Direct link to Keitumetse Madiga's post “Why is the heat of an ice...” Why is the heat of an iceberg greater than that of a pot of boiling water? • (0 votes) Richard a year agoPosted a year ago. Direct link to Richard's post “Heat isn’t something that...” Heat isn’t something that objects possess. Thermal energy, the energy associated with an object’s temperature, is what people usually mean when they say heat. Heat itself is the transfer of thermal energy from one object to another. Thermal energy is the thing that object possess, but heat is a process that occurs between objects. If we compare an iceberg to a pot of boiling water, each of the molecules of both objects have their own amount of thermal energy. All pieces of matter, even very cold ones, have at least some thermal energy because they are in motion at the atomic scale and this is motion is thermal energy. Probably the part that confuses people with a question like this is that a pot of boiling water is hotter than an iceberg and we associated high temperature with thermal energy. Which that is partially true, but temperature is a measure of the average thermal energy of all molecules in a system. The pot’s molecules are on average more energetic than the iceberg’s molecules, but the iceberg has substantially more molecules than the pot. And the total amount of all these iceberg molecule’s thermal energies is greater than the pot’s molecule’s total thermal energy. Hope that helps. (6 votes) Ayudh Saxena 8 years agoPosted 8 years ago. Direct link to Ayudh Saxena's post “Difference between work a...” Difference between work and heat? • (2 votes) Mohamed Ossama 8 years agoPosted 8 years ago. Direct link to Mohamed Ossama's post “Work is a measure of amou...” Work is a measure of amount of energy transferred to the system by applying force on it along the displacement , heat is the process of transferring of energy between two systems due to difference in the temperature (2 votes)Want to join the conversation?
1. Be careful not to call it "Kelvin degree" or "degrees Kelvin." They are called "kelvins" (lowercase K).
2. The temperature in kelvins is still positive, but the CHANGE was negative.
C is the total heat capacity of the object.
s is the specific heat capacity, i.e. the heat capacity per gram.
If you multiply the heat capacity per gram (s) by the number of grams, you get the total heat capacity (C).
Usually you know the specific heat capacity for water, but you don't know the specific heat capacity of the calorimeter.
But it is quite easy to do a separate experiment to determine the total heat capacity of the calorimeter.
heat for water + heat for object + heat for calorimeter = 0
q₁ + q₂ + q₃ = 0.
q₁ = m₁s₁ΔT₁ for the water
q₂ = m₂s₂ΔT₂ for the object
q₃ = CΔT for the calorimeter.
If you then know everything but one of the variables, you can calculate it from the above equations .
and because it was the most basic law they named it zeroth law.
