Chemical reactions test Flashcards
(20 cards)
How can you detect a chemical reaction?
Colour change
Precipitation (solid formed)
Gas given off
Heat given given out
Heat taken in
Light given out
Sound given out
What is an element?
An element is a substance that can’t be broken down into anything simpler and is made of the same type of atom
How many elements are there min the periodic table?
100
What is a mixture?
A mixture is when two or more elements mix together but aren’t chemically joined. E.g- you could have a mixture of compounds
What is a compound?
A compound is when two or more elements chemically join
What are molecules?
Molecules are two or more elements joined together
What gas test burns with a pop?
The test for hydrogen
What is the test for oxygen?
Relights a glowing splint
What gas test causes lime water to turn milky?
Carbon dioxide
How does particle size change the speed of a reaction?
The smaller the particle the faster the reaction
How does concentration change the speed of a reaction?
The higher concentration the faster the reaction
E.G- less water and more acid would create a faster reaction
What is a chemical reaction?
A chemical reaction is when new substances are formed, it can’t be undone
What do word equations represent?
A chemical reaction
What is a physical change?
A physical change is reversible and only changes the state of the substance. NO NEW SUBSTANCES ARE FORMED!!!
State the properties that change when you combine hydrogen and oxygen to make water
Two colourless gases combine to make a colourless liquid
How should you write out an equation if you were combining magnesium and oxygen?
Magnesium +oxygen➡️magnesium oxide
What is the first and second part of a chemical reaction called?
Reactant➡️product
Write the word equation for the reaction in which hydrochloric acid reacts with calcium carbonate, giving off carbon dioxide and producing calcium chloride and water.
Hydrochloric acid+calcium carbonate- carbon dioxide+calcium+chloride+water
What should you always write when doing a word equation in between the reactant and the product?
An arrow ➡️
What is precipitation?
A solid is formed
