Energy Changes Flashcards
Is the reaction between hydrogen and oxygen exothermic or endothermic?
exothermic
Sodium hydroxide reacts with hydrochloric acid in a neutralisation reaction. Will the temperature of the solution increase or decrease during this reaction?
increase
Sodium hydrogencarbonate (bicarbonate of soda) is added to a solution of citric acid. During the reaction, will the temperature go up or down?
it will go down
5g of ammonium nitrate was dissolved in 60g of water in an insulated container. The temperature at the start of the reaction was 23.0°C and at the end it was 18.5°C. Was this an exothermic or an endothermic reaction?
endothermic
Calcium carbonate can be broken down by heating. What is the scientific term for this?
thermal decomposition
During an exothermic reaction, will the temperature of the reaction vessel increase, decrease or stay the same?
increase
In a reversible, endothermic reaction, hydrated copper sulfate is converted to anhydrous copper sulfate and water. Would you expect the reverse reaction to give out or take in energy?
give out energy
Which of the following is NOT an example of an exothermic reaction: Combustion, electrolysis, or neutralisation?
electrolysis
A reaction has taken place, and as a result the mixture has warmed. What type of reaction has taken place?
exothermic
During an _______________ reaction, the temperature increases.
exothermic
During an exothermic reaction, the ______________ increases.
temperature
During an exothermic reaction, the temperature __________.
increases
True or false? Exothermic reactions do not have an activation energy.
false
40 cm3 of acid were mixed with 60 cm3 of alkali in an insulated container. The average temperature of the two solutions before they were mixed was 19.5°C. The temperature after mixing was 27.5°C. Was this an exothermic or an endothermic reaction?
exothermic
Professional sportspeople sometimes use special cooling packs as an alternative to ice packs after an injury. Are these packs based on an exothermic or an endothermic reaction?
endothermic
What is a good insulator?
polystyrene
Polystyrene is a good insulator, so it will prevent _____ ________ during the reaction.
heat transfer
When magnesium is burned in air, large amounts of heat and light are given out. Is this an example of an exothermic or an endothermic reaction?
exothermic
______________ is an exothermic reaction, so temperatures will increase.
neutralisation
Neutralisation is an ____________ reaction, so the temperature would increase.
exothermic
A sports injury pack that turns cold when activated is based on an __________ reaction.
endothermic
________ ________________ reactions absorb heat, so they are endothermic.
thermal decomposition
Thermal decomposition reactions _________ ______, so they are endothermic.
absorbs heat
Thermal decomposition reactions absorb heat, so they are _____________.
endothermic
Name a piece of equipment you would use to check if an endothermic reaction had taken place.
thermometer
A reaction has taken place, and as a result the mixture has cooled. What type of reaction has taken place?
endothermic
When sodium hydrogencarbonate (bicarbonate of soda) is added to a solution of citric acid, the solution becomes cold. Is this an exothermic or endothermic reaction?
endothermic
What name is given to a reaction that takes in energy from the surroundings?
endothermic
To find the ___________ _______ we always do the maximum energy - reactants energy
activation energy
To find the activation energy we always do the ____________ _______ - reactants energy
maximum energy
To find the activation energy we always do the maximum energy - __________ ______
reactants energy
Would the temperature of a reaction vessel during an endothermic reaction increase, decrease or stay the same?
decrease
What name is given to a reaction that gives out energy to the surroundings?
exothermic
Photosynthesis is a reaction in plants that produces carbohydrates from water and carbon dioxide. It requires energy from sunlight. Is this an exothermic or an endothermic reaction?
endothermic
Before a reaction between two particles can happen, the particles need to have a minimum amount of energy. What name is given to this minimum amount of energy?
activation energy
In an exothermic reaction, which is greater: the energy released from forming new bonds, or the energy needed to break existing bonds?
energy released from forming new bonds
In an endothermic reaction, which is greater: the energy released from forming new bonds, or the energy needed to break existing bonds?
energy needed to break existing bonds
When calcium oxide reacts with water, the energy that is released when new bonds form in the product is greater than the energy that is needed to break the bonds in the reactants. What type of reaction is this?
exothermic
During a chemical reaction, is energy supplied or released when bonds are broken?
supplied
When ethanoic acid reacts with sodium carbonate, the energy that is needed to break the existing bonds in the reactants is greater than the energy that is released when new bonds form in the products. What type of reaction is this?
endothermic
During a chemical reaction, is energy supplied or released when bonds are formed?
released
True or false? A chemical change involves an energy change.
true
