Unit 6 review

The temperature of an unknown piece of metal with a mass of 30.00 g changes from 25.0 °C to 35.0 °C when the metal absorbs 350.0 J of energy. What is the specific heat of the metal?

• 1.17 J/g°C
• -1.17 J/g°C
• 0.857 J/g°C
• -0.857 J/g°C

Tags

NGSS.HS-PS3-1

What mass of P₄ must be reacted to produce 5905 kJ of energy?

P₄ + 6Cl₂ → 4PCl₃ ΔH = −2439 kJ

• 25.43 g

• 563.0 g

• 2.421 g

• 300.0 g

Using the following information, calculate ΔH for the reaction CH₄ (g) + NH₃ (g) → HCN (g) + 3H₂ (g)

N₂(g) + H₂(g) + 2C(s) → 2 HCN(g) ΔH = +270.3 kJ

N₂ (g) + 3 H₂ (g) → 2 NH₃ (g) ΔH = -91.8 kJ

2 H₂ (g) + C (s) → CH₄ (g) ΔH = -74.9 kJ

• 256.0 kJ

• -1628.2 kJ

• -6387 kJ

• 329.3 kJ

What is the change in internal energy if a system absorbs 67 kJ of heat while the surroundings transfer 32 kJ of work to the system.

• 99 kJ

• 35 kJ

• -35 kJ

• -99 kJ

Given samples of the same size, all heated in the same way for the same length of time, which will have the greatest change in temperature?

• air

• aluminum

• gold

• mercury

What is ΔH if 2 mol of O₂(g) is consumed in this reaction?

H₂(g) + ½ O₂(g) → H₂O(l) ∆H = −285.8 kJ

• -570 kJ

• -71.45 kJ

• -1143.2 kJ

• -142.9 kJ

Which of the following has a ΔH_f^o value of 0?

• I₂(g)

• N(g)

• NO₂(g)

• He(g)

Use the H_f values in the table below to calculate ΔH_rxn for:

CO_2(g) + N_2(g) ⟶ NO_(g) + CO_(g) ΔH = ?

ΔH_r kJ/mol

CO(g) = −110.

CO₂(g) = −394

NO(g) = 90.

• −370 kJ/mol

• 374 kJ/mol

• −333 kJ/mol

• 335 KJ/mol

Which is an enthalpy of formation (ΔH_f) equation?

• Na(g) → Na⁺(g) + e^- ΔH = -364 kJ/mol

• C₂H₅OH(l) + 3O₂(g) → 2CO₂(g) + 3H₂O (l) ΔH = −1286 kJ/mol

• 2C(s) + 2H₂(g) → C₂H₄(g) ΔH = −52.3 kJ/mol

• Na⁺(g) → Na⁺(aq) ΔH = −364 kJ/mol

Given, C(s) + O₂(g) → CO₂(g) + 60.kJ, what is the value for ΔH for the reaction?

• +60. kJ

• −60. kJ

• there is no way to know