Thermodynamics Review District test

ΔH value in an endothermic reaction is a positive number.

• True
• False

 _?_  is the amount of energy required to raise the temperature of 1 gram of any substance 1^oC.

• Specific heat
• A calorie
• Thermal energy
• Conduction

As 120 g of hot milk cools in a mug, it transfers 20, 000 J of heat to the environment. What is the temperature change of the milk? The specific heat of milk is 2.6 J/g·°C. (Q=mcΔT)

• 64 °C
• 1.56 °C
• 640 °C
• cannot be determined

If 100 g of aluminum at 145ºC gains 6,800 J of heat, what is the final temperature (T_final) of the aluminum? Aluminum has a specific heat of 0.897 J/gºC. (Q=mcΔT)

• -69°C
• 0.52°C
• 221°C

The Q of water is 100. If he ΔT=20⁰C and the change in mass of the biscuit, Δm =1.35g.Find the enthalpy of the biscuit in kJ/g. (Q=mcΔT)

• 6.19
• 61.9
• 6193
• 3.703

The Q of water is 200. If he ΔT=45.6⁰C and the change in mass of the biscuit, Δm =5.35g.Find the enthalpy of the biscuit in kJ/g. (Q=mcΔT)

• 7126
• 0.8189

• 7.13
• 38.12

How much heat does an aluminum block absorb if 10.00 grams ae heated from 25.0^oC to 50.0^oC? the specific heat of aluminum is 0.900J/g^oC

• 450
• -450
• 225
• -225

How do you calculate Enthalpy of a reaction?

• ΔH = ΔH_products - ΔH_reactants

• ΔT = q / mC

• ΔG = ΔH -TΔS

• E = mc²

Which statement is true regarding endothermic reactions?

• a) Temperature change is positive and enthalpy change is positive
• b) Temperature change is positive and enthalpy change is negative
• c) Temperature change is negative and enthalpy change is positive
• d) Temperature change is negative and enthalpy change is negative

Endothermic reactions feel

• warm
• cold