Energy changes

Endothermic or exothermic: energy is transferred to the surroundings

Exothermic

Endothermic or exothermic: the temperature of the surroundings increases

Exothermic

Exothermic or endothermic: combustion, oxidation and most neutralisation reactions

Exothermic

Exothermic or endothermic: self-heating cans and hand warmers

Exothermic

Exothermic or endothermic: energy is taken from the surroundings

Endothermic

Exothermic or endothermic: the temperature of the surroundings decreases

Endothermic

Exothermic or endothermic: thermal decomposition reactions and the reaction of citric acid and sodium hydrocarbonate

Endothermic

Exothermic or endothermic: instant ice packs

Endothermic

Energy is _____ when bonds are broken or bonds are formed

Transferred

During a chemical reaction, bonds in the ____ are broken and new bonds are made in the _____ (give answer in the form ____, ___)

Reactants, products

Exothermic or endothermic: more heat energy is released in making bonds than is taken in when breaking bonds in the reactants

Exothermic

Exothermic or endothermic: less heat energy is released in making bonds than is taken in when breaking bonds

Endothermic

Does the energy level diagram show and exothermic or an endothermic reaction?

Exothermic

Does the energy level diagram show an exothermic or an endothermic reaction?

Endothermic

What is defined as ‘the minimum energy needed by particles when the collide, for a reaction to occur’

The activation energy

In the profile for an exothermic reaction, the overall energy change is _____

Negative

In the profile for an endothermic reaction, the overall energy change is _____

Positive

The answer is _____ KJmol to the power of -1

-486

Chemical cells use ____ ____ to transfer energy by electricity

Chemical reactions

Connecting two different metals in contact with an electrolyte makes a ____ _____

Simple cell

What is one example of a non-rechargeable cell?

An alkaline cell

In a non-rechargeable cell, a voltage is produced until until one of the reactants is used up and the battery ____ ____

Goes flat

In chemical cells, swapping the two electrodes means that the recorded voltage becomes _____

Negative

The biggest voltage in a chemical cell occurs when the difference in the reactivity of the two metals is the _____

Largest

Which will have a higher voltage, a chemical cell made from magnesium and copper or a cell made from magnesium and silver?

A cell made from magnesium and silver

What type of cell will continuously produce a voltage as long as it has a constant supply of a suitable fuel and oxygen?

A fuel cell

In a fuel cell, the fuel is oxidised _____ rather than being burned so reaction can take place at a lower temperature

Electrochemically

In a fuel cell, the energy is released as _____ energy not thermal energy

Electrical

What is a good alternative to rechargeable cells and batteries?

Hydrogen-oxygen fuel cells

What is the only product formed in a hydrogen-oxygen fuel cell?

Water

Which type of cell is cheapest to manufacture?

An alkaline cell

Which type of cell may end up in landfill or is very expensive to recycle?

An alkaline cell

Which type of cell can be charged many times, limiting the amount of resources used?

A rechargeable cell

Which type of cell is quite expensive to manufacture?

A rechargeable cell

Which type of cell is easy to maintain as there are no moving parts?

A hydrogen fuel cell

Which type of cell is small in size?

A hydrogen fuel cell

Which type of cell has water as its only product?

A hydrogen fuel cell

Which type of cell is very expensive to manufacture?

A hydrogen fuel cell

Which type of cell needs a supply of a flammable gas?

A hydrogen fuel cell

Which type of cell is used in spacecraft?

A hydrogen fuel cell