Science Chapter 8 Flashcards
Ace science
What do you call a substance that reacts with oxygen to make burning reaction
fuel
What is burning
a chemical reaction in which a substance combines with oxygen.
Give examples of fuels
Charcoal,wood,coal,natural gas and oil
Describe what happens when fuel burns
the chemical energy is changed into thermal, light and sound energy.The energy dissipate(spread out) into the surroundings
What is another term for burning
Combustion
What do you call a chemical reaction in which energy to given out to surroundings
Exothermic reaction
which reaction is the combustion of hydrogen
Exothermic reaction
Hydrogen+ Oxygen =
Water
What is an example of the exothermic reaction of other substances burning in air
Magnesium-> oxygen + Magnesium oxide
Burning magnesium that creates magnesium oxide.
Energy is given out as heat and light as the magnesium and oxygen rearrange themselves
What is an oxidation reaction
any reaction in which a substance combines with oxygen
Potassium+water=
Potassium hydroxide+ hydrogen
What is formed when a substance burn and combines with oxygen
Oxide
what type of particles/atoms water is made up of
Hydrogen and oxygen
Magnesium+ hydrochloric acid=
magnesium chloride+ hydrogen
Explain what happens in the potassium and water reaction
The bond between the hydrogen and oxygen in the water break. the atoms rearrange to form potassium hydroxide and hydrogen. Stored chemical energy is changed to thermal energy, and dissipates into the environment
sodium hydrogencarbonate+ citric acid=
sodium citrate+water++carbon dioxide
Explain what is Endothermic reaction
When a chemical reaction absorb thermal energy from their surroundings and change it to chemical energy stored in chemical bonds.
When endothermic reaction takes place, the temperature at the end is lower than at the start of the reaction.
What happens when sodium
sodium hydrogencarbonate+ citric acid= sodium citrate+water++carbon dioxide
Thermal energy is absorbed from the surroundings and stored in the form of chemical bonds, in the test tube, the surroundings will have a lower temperature and the test tube will feel cooler
Explain how Ice melting is an Endothermic Process
Thermal energy is absorbed from the surroundings as the solid ice changes to liquid water.
As the particles absorb thermal energy from the surroundings, they vibrate more and more and the ice begins to melt.
Explain the difference between Endothermic and Exothermic process
Exothermic process: thermal energy is given out
Endothermic process: thermal energy is taken in
What are some examples of Metal Reaction with Water
Pottasium + water = Potassium hydroxide+ hydrogen
lithium+ water= lithium hydroxide+ hydrogen
Sodium+ water= sodium hydroxide+ hydrogen
What is the general equation for the reaction of a metal with acid,water,oxygen
Metal + acid= metal salt + hydrogen
Metal+water= Metal hydroxide+ hydrogen
metal+ oxygen = Metal oxide + Metal Oxides
What are Equations for reaction with hydrochloric
Magnesium+ hydrochloric acid= magnesium chloride+ hydrogen
aluminium + hydrogen acid= aluminium chloride+ hydrogen
zinc+ hydrochloric acid= Zinc chloride+ hydrogen
What are the products of metal reacts with an acid
salt( metal chloride/metal sulfate/metal nitrate and hydrogen gas
When a metal reacts with hydrochloric acid, the SALT produced is…
metal chloride
When a metal reacts with sulfuric acid, the SALT produced is…
Metal sulfate
When a metal reacts with nitric acid, the SALT produced is…
metal nitrate
When do metals corrode
when they are left in contact with air or water
What is it called when iron corrodes
it is called rusting
What is Rusting?
Rusting is the oxidation reaction of iron with oxygen in the presence of water
How fast does the most reactive metal corrode?
quickly
How fast does the leastreactive metal corrode?
Slowly
Iron + Oxygen=
Iron oxide
People who live by the seaside often claims their car go rusty faster
Does the salt speed up the rate of rustling reaction?
Yes it does.
1.Covered tube with dried air , nail and calcium chloride
- .Covered tube with air , nail and distilled water
3..Covered tube with layer of oil , nail and boiled water
4..Covered tube with air , nail and salt water
Explain the conditions of these nails after some time
- Does not rust
2.rust
- Does not rust
4.rusts quickly
Methods to prevent things from rusting
1.Painting
2.Galvanishing
- Plastic Coating
4.Oiling
2Ca(S)+ O2(g)=
2Cao(s)
What happens when metal reacts with water?
The metal burns, a bright flame/spark is produced
How do you know if the metal and water reaction stopped?
1.No more flames
2.Light turned to dark
What is the chemical name for rusting
Iron Oxide
What is the difference between an endothermic reaction and an endothermic process
Endothermic reaction is the change of a substance to a new one with different chemical identity meanwhile an endothermic process is the method of changing one or more chemicals. For example, ice is being heated and the particles evaporate into gas form.
