Chemical Properties And Formulate Flashcards
Chemical reaction - what are the signs that a chemical reaction has taken place
Colour change
Gas produced
Solid formed from solution
Energy change
A change in which one or more chemical are formed
Involves- temperature, fire, explosion,colour,odour,bubbles and fizz
Word equations
Sodium (Na)+ water (H2O) =
Sodium hydroxide and hydrogen
What happens to the mass of the elements after a chemical reaction
In a chemical reaction the atoms are rearranged to make PRODUCTS. No atoms are made or lost.
Therefore the mass is the SAME
What is a chemical reaction
Atoms are rearranged to make new substances
The NEW compound is totally DIFFERENT from the original elements
A solid changes to a liquid- when
At its melting point
A solid changes to a liquid- when
At its melting point
Are changes of state reversible
Yes- the state can be changed back by changing the temperature
Eg water can be heated to change to gas, but can be cooled to be water and frozen to be ice and melted to be water again
What are properties of a substance mean
A physical property include melting point, boiling point, color, density, hardness.
A chemical property include flammability, pH, reaction with acid
What is the difference between a physical and chemical property
A physical change is what you see. But no new substance is formed.
A chemical change - a chemical reaction occurs. A new substance is formed
Are changes of state reversible
Yes- the state can be changed back by changing the temperature
Eg water can be heated to change to gas, but can be cooled to be water and frozen to be ice and melted to be water again
What are properties of a substance mean
A physical property include color, density, hardness, and melting and boiling points.
A chemical property describes the ability of a substance to undergo a chemical change.
What is the difference between a physical and chemical property
A physical change is what you see. But no new substance is formed.
A chemical change - a chemical reaction occurs. A new substance is formed
How do we use melting and boiling points to predict state
Can predict if it’s a solid, liquid or gas
A solid changes to a liquid- when
At its melting point
Are changes of state reversible
Yes- the state can be changed back by changing the temperature
Eg water can be heated to change to gas, but can be cooled to be water and frozen to be ice and melted to be water again
