Chemical Reactions Flashcards
Fill in the missing words in these indicators of a chemical reaction:
Production of a _____, effervesense (_______ or bubbling).
Temperature ________.
_______ of light.
________ colour change.
Formation of a _________ (an insoluble solid formed from solutions)
Production of a GAS, effervesense (FIZZING or bubbling).
Temperature CHANGE.
PRODUCTION of light.
PERMANENT colour change.
Formation of a PRECIPITATE (an insoluble solid formed from solutions)
During a chemical reaction atoms are rearranged to form what?
different compounds or elements and compounds.
what scale is used to show the strength of acids and alkalis?
PH scale
what is the range on the pH scale of acids?
0 - 6
Is 6 on the pH scale a strong or weak acid?
weak acid
what is the range on the pH scale of alkalis?
8-14
is 13 on the pH a strong Acid or Alkali?
Alkali
What number on the pH scale represents a neutral substance?
7
what is added to a liquid to give a pH reading?
colour universal indicator
what does pH stand for?
potential of Hydrogen
give 2 examples of common acids
lemon, vinegar, orange juice
give 2 examples of common alkalis found in a home
bleach, soap, baking soda
where on the pH scale would tap water commonly sit?
pH 7
where on the pH scale would stomach acid commonly sit and would the indicator give a red or purple result?
pH 1 - strong red
what colour would a substance that is neutral on the pH scale usually turn with universal indicator
Green
what type of reaction is described here:
A chemical reaction where an acid reacts with an alkali to form salt and water.
Neutralisation reaction
what is the general word equation for a neutralisation reaction?
Acid + Alkali —-> Salt + Water
When naming salts formed in neutralisation reactions does the first word come from the acid or the alkali?
Alkali, the second word comes from the acid.
what are the the products from this reaction:
Hydrochloric Acid + Sodium Hydroxide
—-> Sodium Chloride + Water
When a substance is burned in air what element from the air is it reacting with?
Oxygen
What colour flame is produced when magnesium is burned in air?
bright white
what are the 3 indicators that a chemical reaction is taking place when magnesium is burned in air?
- production of light, 2. temperature change, 3. change in appearance.
what is produced when magnesium is burned and reacts with oxygen?
Magnesium + Oxygen —> Magnesium Oxide
what is the product of this reaction:
2Mg + O2
2MgO
Describe combustion
fuel is burned in oxygen to release light and energy
What 3 things are needed for combustion to take place?
- Oxygen, 2. Heat, 3. Fuel
What is a compound of Hydrogen and Carbon called
Hydrocarbon
what is the word equation to describe complete combustion of a hydrocarbon
Hydrocarbon + Oxygen —> Carbon Dioxide + Water
Is complete or incomplete combustion used to describe the process of a Hydrocarbon burning in limited oxygen?
Incomplete
Is complete or incomplete combustion used to describe the process of a Hydrocarbon burning in excess oxygen?
Complete
What is produced when incomplete combustion of a hydrocarbon take place?
either CO (Carbon Monoxide) + Water, or C (Carbon) + Water
What is the name of a reaction that releases energy as either heat or light?
Exothermic
Why are some reactions exothermic
the total energy of the product is less than the total energy of the reactants.
Describe endothermic reactions
Reactions that take in energy from the surroundings
Is mass lost or gained in chemical reactions?
No - no mass is lost or gained.
What is the common name for the gaining of oxygen in a chemical reaction?
Oxidation
what is described here:
A substance reacts and combines with Oxygen.
An oxidation reaction.
is combustion an oxidation reaction?
Yes
Give an (not combustion) example of a common oxidation reaction
Rusting
In rusting what element is reacting with the Oxygen in the air?
Iron to form Iron oxide.
Give the word formula for rusting
Iron + Oxygen —> Iron Oxide
