Unit 9 Test

The sun shines down on this family as the play on the beach.

• conduction
• convection
• radiation

Which direction will the heat flow while this person holds a hot cup of tea?

• from the cup to her hand
• from her hand to the cup
• no heat is transferred

Endothermic or Exothermic? -- A SYSTEM RELEASES OR GIVES OFF HEAT

• Endo

• Exo

Endo or exo? (System = melting snowman)

• Endo

• Exo

What is true of this reaction?

• Equal amounts of energy were released and absorbed
• The reaction released more energy than it absorbed
• The reaction absorbed more energy than it released

Calculate the change in enthalpy, ΔH, for the reaction:

2NaCl (s) -----> 2Na (s) + Cl₂ (g)

(ΔH NaCl = -411 kj)

• 822 kJ

• -822 kJ

• 411 kJ

• -411 kJ

20 g of water. specific heat of water is 4.18 J/g°C. temperature changes from 25° C to 20° C, how much heat energy (Q) moves from the water to the surroundings?

• 418 J

• 209 J

• 83 J

• 4.18 J

The specific heat(c) of copper is 0.39 J/g °C. What is the final temperature (T_f) if the initial temperature was 0^oC when 100 Joules of heat(Q) is added to 20 grams?

• 12.82 °C

• 24.12°C

• 1.95 °C

• 5128 °C

Endo or exo? (system = egg)

• Endo

• Exo

What is the formula used to calculate Heat Energy?

• Q = mc(T_f - T_i)

• PV = nRT

• ΔHrxn = Sum of ΔH_f Products - Sum of ΔH_f Reactants