Oquizy

Why is a flame or spark needed to start an exothermic reaction?

To form stable bonds To increase pressure To lower activation energy To supply energy to break initial bonds

Which statement correctly defines enthalpy change (ΔH)?

The change in energy of bonds only The energy needed to start a reaction The heat change at constant pressure The temperature change of the surroundings

Which is most reactive based on energy released?

Fe Mg Same Zn

What type of reaction does this diagram represent?

Combustion only Endothermic Exothermic Reversible

What does arrow 1 represent?

Activation energy Bond energy of products Energy released Enthalpy change

A student heats 50.0 g of water from 20 °C to 30 °C. Given c = 4.18 J/g°C for water.
What is the energy absorbed? What is the energy absorbed?

209 J 2090 J 4180 J 50 J

Quiz: Chemistry - Chemical Energetics