Enthalpy Changes
Chemistry ⇒ Thermochemistry and Energetics
Enthalpy Changes starts at 10 and continues till grade 12.
QuestionsToday has an evolving set of questions to continuously challenge students so that their knowledge grows in Enthalpy Changes.
How you perform is determined by your score and the time you take.
When you play a quiz, your answers are evaluated in concept instead of actual words and definitions used.
See sample questions for grade 10
A chemical reaction has ΔH = -250 kJ/mol. What does the negative sign indicate?
A reaction has an enthalpy change of +80 kJ/mol. Will the temperature of the surroundings increase or decrease?
A reaction has ΔH = +150 kJ/mol. Is this reaction endothermic or exothermic?
A student dissolves ammonium nitrate in water and observes the temperature drops. What type of enthalpy change is this?
A student dissolves ammonium nitrate in water and observes the temperature drops. What type of enthalpy change is this?
A student mixes hydrochloric acid and sodium hydroxide in a beaker and notices the temperature increases. What can be said about the enthalpy change of this reaction?
Calculate the enthalpy change for the reaction: 2H2(g) + O2(g) → 2H2O(l), given ΔHfo [H2O(l)] = -286 kJ/mol.
Calculate the enthalpy change for the reaction: C(s) + O2(g) → CO2(g), given ΔHfo [CO2(g)] = -394 kJ/mol.
Which of the following is a standard state for oxygen? (1) O2(g) at 298 K and 1 atm (2) O2(l) at 273 K and 1 atm (3) O3(g) at 298 K and 1 atm (4) O2(g) at 100°C and 1 atm
Which of the following is NOT a standard condition for measuring enthalpy changes? (1) 298 K temperature (2) 1 atm pressure (3) 1 mol/L concentration for solutions (4) 100°C temperature
Which of the following is NOT an enthalpy change? (1) Enthalpy of formation (2) Enthalpy of combustion (3) Enthalpy of vaporization (4) Enthalpy of pressure
Which of the following is the best definition of the standard enthalpy change of reaction? (1) The enthalpy change when one mole of a compound is formed from its elements. (2) The enthalpy change when a reaction occurs in the molar quantities shown in the equation under standard conditions. (3) The enthalpy change when one mole of a substance is burned in oxygen. (4) The enthalpy change when one mole of a substance is dissolved in water.
Fill in the blank: The enthalpy change when one mole of a compound is formed from its elements in their standard states is called the standard enthalpy of ______.
Fill in the blank: The enthalpy change when one mole of a solid is converted to liquid at its melting point is called the enthalpy of ______.
Fill in the blank: The enthalpy change when one mole of a substance is completely burned in oxygen is called the enthalpy of ______.
Fill in the blank: The enthalpy change when one mole of a substance is converted from liquid to gas at constant pressure is called the enthalpy of ______.
State whether the following statement is true or false: Endothermic reactions have a positive enthalpy change.
State whether the following statement is true or false: The enthalpy change of neutralization is always negative.
The enthalpy change for a reaction is negative. Is the reaction exothermic?
True or False: The enthalpy change of a reaction can be determined using calorimetry.
