Substances and chemical reactions

Question Answer
What is the name of a process where gases are converted to liquids? Condensing
What state of matter is produced as a result of melting? Liquid
Which state of matter can change its shape and its volume? Gas
Which state of matter has the smallest spaces between its particles Solid
What happens to all matter when it is heated? It expands
Everyday example of expansion/contraction? Water in pipes in winter can freeze and expand causing them to burst.
What are the four signs of chemical reaction? Colour change, Gas being formed, Solid being formed, a change in energy
What is always formed by a chemical reaction? A new product
What is meant by a term Non Newtonian fluid? Non Newtonian fluid is a substance that sometimes behaves like a solid and sometimes like a liquid
Which is a faster chemical reaction: iron rusting or a firework going off? A firework going off is a faster chemical reaction.
Is salt dissolving in water a chemical or a physical reaction? Salt dissolving in water is a physical reaction.
Why is salt dissolving in water not a chemical reaction? There is no new product formed. Water can be evaporated and salt would remain behind.
What are three ways of speeding up a chemical reaction? Increase concentration, decrease particle size and increase temperature
What are three ways of slowing down a chemical reaction? Decrease concentration, increase particle size and decrease temperature
What name is given to a substance that can change its shape but not its volume? Substance that can change its shape but not its volume is called a liquid.
What kind or reactions are breaking glass, ice melting, paint drying, water boiling? These are physical reactions
What kind of reactions are frying an egg and gas explosion? These are chemical reactions
Which is the only sign of chemical reaction that is present in every chemical reaction? A change in energy
What instrument do we use to measure temperature? A thermometer.
Name two examples of Non Newtonian liquid Custard and mayonnaise.
What are the three states of matter? Solid, liquid and gas
How are particles arranged in a solid? The particles are very close together
What happens at the melting point of a substance? A solid changes into a liquid
When a solid expands what happens to its particles? They move further appart
All liquids have a fixed volume and take the shape of their container. True or False True
Is burning of petrol a physical reaction? No burning petrol is a chemical reaction
A bee sting is acidic. Which would neutralise it baking soda or alcohol? Baking soda
Which solution is more concentrated: 6g of salt + 60 ml of water or 10g of salt + 60 ml of water 10g of salt + 60 ml of water is more concentrated
If water is added to acid the acid becomes less acidic and its pH goes down. True or false? False, it becomes less acidic and its pH goes UP!
What is meant by a term catalyst? A substance that speeds up a reaction and is not used up in the process
What is a name for biological catalyst found in living things? An enzyme
How would you measure a pH of a hydrochloric acid solution? Add a drop of universal indicator and check the colour of the solution against a pH colour chart.
What are the two substances produced when you add potassium hydroxide to hydrochloric acid? potassium chloride and water
What are the two factors needed for rusting to take place? Oxygen and moisture (water) are present
State one way to protect iron from rusting Use paint
Iron rusts faster if it is put in sea water. Why is that? Sea water contains salt which speeds up the rate of rusting.
Out of: aluminium, copper, zinc and potassium which one would produce bubbles of hydrogen gas if put in water? Potassium

Hi there, would you like to get such a paper? How about receiving a customized one? Check it out