Thermochemistry Review

The standard enthalpy of formation

(ΔH_f) of gaseous water is zero.

• True

• False

SL: The standard enthalpy of formation

(ΔH_f) of gaseous O₂ is zero.

• True

• False

Tags

NGSS.HS-PS3-1

The enthalpy change when one mole of gaseous ions is surrounded by water molecules to produce a solution of infinite dilution at 298 K and 100 kPa.

• Standard enthalpy of hydration

• Standard enthalpy of solution

• Lattice enthalpy

• Standard enthalpy of atomisation

The enthalpy change when one mole of an ionic compound is broken into its constituent gaseous ions at 298 K and 100 kPa.

• Standard enthalpy of hydration

• Standard enthalpy of solution

• Lattice enthalpy

• Standard enthalpy of atomisation

Which of the following equations represents the C−Cl bond enthalpy in CH₃Cl?

• Cl_2(g) → 2 Cl_(g)

• CH₃Cl_(g) → CH_3(g) + Cl_(g)

• CH₃Cl_(l) → CH_3(g) + Cl_(g)

• CH₃Cl_(g) → CH₃⁺_(g) + Cl^-_(g)

Tags

NGSS.HS-PS1-4

Which of the following show an increase in entropy? Select all correct answers.

• H₂O_(g) → H₂O_(l)

• NaCl_(s) → Na⁺_(ag) + Cl⁻_(aq)

• 2C₄H_{10 (g)} + 13 O_{2 (g)} → 8 CO_{2 (g)} + 10 H₂O _(l)

• CaCO_{3 (s)} → CaO _(s) + CO_{2 (g)}

Which combination of ΔH θ and ΔS θ will result in a non-spontaneous reaction at all temperatures?

• Positive, positive

• Positive, negative

• Negative, negative

• Negative, positive

In an exothermic reaction, heat is ...

• taken in

• given out

Tags

NGSS.HS-PS1-4

In an endothermic reaction, heat is ...

• taken in

• given out

Tags

NGSS.HS-PS1-4

A student mixed two chemicals to allow them to react. The temperature before the reaction was 25 ° C. The temperature after the reaction was 18° C. Which of the following is true?

• It is an exothermic reaction

• It is an endothermic reaction

Tags

NGSS.HS-PS1-4