In an exothermic reaction, the enthalpy change (Δ H) is:
- APositive
- BNegative
- CZero
- DUnpredictable
The SI unit of heat or thermal energy is the:
- ACalorie
- BJoule
- CNewton
- DKelvin
The amount of heat required to raise the temperature of one gram of water from 14.5°C to 15.5°C is called:
- A1 Joule
- B1 Calorie
- C1 Kelvin
- D1 Enthalpy
The relationship between heat of reaction and enthalpy change at constant pressure is:
- Aqp = -Δ H
- Bqp = Δ H
- Cqp = 0
- Dqp = Δ S
Which of the following processes is endothermic?
- ACombustion of methane
- BFreezing of water
- CSublimation of dry ice
- DCondensation of steam
The standard state for a gas is:
- A1 atm pressure
- B1 M concentration
- C0°C
- D2 atm pressure
The energy required to break a bond of the same type in one mole of a substance is called:
- ALattice energy
- BBond energy
- CIonization energy
- DElectron affinity
When a reaction is reversed, the magnitude of Δ H remains the same but its:
- AValue becomes zero
- BSign changes
- CUnit changes
- DMagnitude doubles
In an endothermic reaction, the products have:
- ALower energy than reactants
- BHigher energy than reactants
- CThe same energy as reactants
- DNo energy
The heat capacity of a substance is expressed in:
- AJoules
- BJoules per Kelvin
- CJoules per gram per Kelvin
- DKelvin
