q(joules) = mass * specific heat * change in temperature ( 8 kg = 8000 grams )
q = (8000 grams H2O)(4.180 J/gC)(70o C - 20o C)
= 1.7 X 106 joules
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1 joule = 2.39 X 10-4 kcal 65-30 = 35 degrees 1 kcal = 1 degree kg 35 degrees X 0.5 kg / 2.39 X 10-4 kcal/joulle = 73222 joules
E = mass x specific heat x Δ°T Δ°T = new temperature - original temperature where Δ°T is equal to temperature change (Celsius in this case). The specific heat of Al is 0.900 J/g°C. Before we proceed to find the quantity of heat in joules, we must first find the temperature change. To calculate the temperature change, we must subtract the original temperature from the new temperature. Δ°T = 50°C - 25°C = 25°C In order to find the quantity of heat (joules), we must multiply mass, specific heat, and the temperature change (calculated above). E = 40.0g x 0.900 J/g°C x 25°C = 900 Joules or 9.0 x 102 Joules
58 F
In order to walk from 15 below ground to 45 above ground, you have to climb a total of 60 floors.
You need the heat capacities for these substances in order to answer this question. If you have those, it's simple algebra.
1 joule = 2.39 X 10-4 kcal 65-30 = 35 degrees 1 kcal = 1 degree kg 35 degrees X 0.5 kg / 2.39 X 10-4 kcal/joulle = 73222 joules
E = mass x specific heat x Δ°T Δ°T = new temperature - original temperature where Δ°T is equal to temperature change (Celsius in this case). The specific heat of Al is 0.900 J/g°C. Before we proceed to find the quantity of heat in joules, we must first find the temperature change. To calculate the temperature change, we must subtract the original temperature from the new temperature. Δ°T = 50°C - 25°C = 25°C In order to find the quantity of heat (joules), we must multiply mass, specific heat, and the temperature change (calculated above). E = 40.0g x 0.900 J/g°C x 25°C = 900 Joules or 9.0 x 102 Joules
In order for snow to occur, the ground temperature must be a temperature of 32 degrees or lower.
In order to answer this question, you need the enthalpy of fusion of ice, which is 333.55 J/g (Joules/gram). The enthalpy of fusion is the amount of heat that must be absorbed or lost in order to change physical state. The number of Joules required to melt the ice = enthalpy of fusion of ice x mass of ice. Joules needed to melt the ice = 333.55 J/g x 40 g = 13342 J
E = mass x specific heat x Δ°t (temperature change)------------------ Energyspecific heat * temperature change = massΔ°t = new temperature - original temperatureIn order to calculate the mass of water able to be heated, we must divide the given energy by the result of specific heat times temperature change. Before proceeding to do such, we must calculate the temperature change, as well as convert cal to joules. It is also important to know that water's specific heat is 4.184 J/g°C.1. Calculate temperature change.Δ°t = 100°C-25°CΔ°t= 75°C2. Convert kcal to joules (multiply kcal * 103 * 4.184 joules [J]). (kcal --> joules)Joules = 4.22 kcal x 103 cal x 4.184 J/g°C = 17656.48 Joules------------------------ 1 kcal ------ 1 cal3. Find mass.Mass = 17656.48J(4.184J/g°C * 75°C) = 56.3g
Fahrenheit is a temperature scale in which water freezes at 32 degrees and boils at 212 degrees
82 degrees C !!!
E = mass x sp ht x Δ°tIn order to calculate the final temperature change, we must also find the temperature change.1. Find the temperature change.Divide joules by (mass x specific heat).Δ°t = 40,000J/500.0g x 4.184J/g°CΔ°t = 19.1°C2. Calculate the final temperature.Tf = 10.0 - 19.1Tf = -9.1°CThere was a decrease in temperature, indicating that it was an endothermic reaction (as energy was removed as stated in the question).
In order for water to reach it's boiling point, then the temperature has to reach 212 degrees. 212 degrees is for about sea level. it will vary depending on where you are.
According to the NHL, the ice is supposed to remain between 20 and 22 degrees Fahrenheit; with 22 degrees being the optimal ice temperature. The temperature inside the arena itself is supposed to remain below 65 degrees.
In order to answer this question, you need the enthalpy of fusion of ice, which is 333.55 J/g (Joules/gram). The enthalpy of fusion is the amount of heat that must be absorbed or lost in order to change physical state. The number of Joules required to melt the ice = enthalpy of fusion of ice x mass of ice. 1 kg = 1000g 40kg x (1000g/1kg) = 40,000g Joules needed to melt the ice = 333.55 J/g x 40000 g = 13342000 J or 1.3342 x 107 J
E = mass x sp ht x Δ°t (Finding Energy)where E (Energy) or Q (Quantity of Heat), mass (g), sp ht (aka specific heat, J/g°C*[typical] or cal/g°C or kcal/g°C), and Δ°t (temperature change). Finding Temperature ChangeDivide energy by mass multiplied by specific heat. Δ°t = Energy-- Mass * sp htIn order to find the final temperature (if problem is asking for this), add or subtract the original temperature and the new temperature together.Tf = original temperature +/- new temperatureIf energy is added, the temperatures will be added together; if energy is removed, the temperatures will be subtracted.Finding MassDivide energy by specific heat multiplied by temperature change. Mass = Energy------- sp ht * Δ°tFinding Specific HeatDivide energy by mass multiplied by temperature change. Sp ht = Energy------- Mass * Δ°tConverting Form of Energy (joules, kcal, and cal)Sometimes a problem will have E be shown in cal/g°C or kcal/g°C but will be asking for Joules or even vice versa. This means a conversion has to take place. Cal --> Joules and Joules --> cal-Calories (Cal) --> Joules (J)Multiply # cal by 4.184 Joules (J).Conversion Factor# cal x 4.184 J = Joules---------- 1 cal1 cal = 4.184 Joules-Joules (J) --> Calories (Cal)Divide # Joules (J) by 4.184Conversion Factor# J x 1 cal = cal--- 4.184 J1 Joule = 0.239005736 calKcal --> Joules (J) and Joules (J) --> Kcal-Joules --> kcal (Joules --> cal --> kcal)Divide # J by # kcal multiplied by 103Conversion Factor# Joules x 1 cal - * - 1kcal = kcal---------- 4.184J -- 103 cal1 kcal = 4,184 Joules 1 Joule = 0.000239005736 kcal-Kcal --> Joules (J) (Kcal --> cal --> Joules)Multiply # kcal by 103 cal by 4.184JConversion Factor# kcal * 103 cal * 4.184J = Joules (J)----------- 1 kcal --- 1 calAnother relationship that is good to understand: 1 kcal = 1000 (103) cal 1 cal = 0.001 (10-3) kcal