Year 10 final atoms revision

by john west | Jun 20, 2012 | school posts, Year 10, K-11

Final homework on this topic. There are 20 questions so it will take longer than your usual homework. Good luck with the test on tuesday.

Decomposition reactions year 10

by john west | Jun 12, 2012 | school posts, Year 10, K-11

Homework:

Here are some notes you need for this part of the topic. Copy them into your book ready for tomorrow. Look at the short video as well

Write in the date followed by the heading Decomposition Reactions: now copy in the rest of your notes

•Decomposition reactions occur when a large molecule is broken down into two or more simpler substances.

•Some molecules are so unstable they literally fall apart (nitrogen triodide, NI₃)

Other substances, many carbonates for instance require heat before they break down into simpler molecules. Hydrogen peroxide is another chemical which is not very stable and undergoes a decomposition reaction when it is treated with a catalyst.

Heating carbonates:

•Carbonates other than sodium and potassium decompose on heating.

•Copper carbonate is a green powder

•When it is heated strongly it turns to a black powder.

•This black powder is copper oxide.

•Copper carbonate has the chemical formula CuCO₃

•Copper oxide has the chemical formula CuO

•As well as the black powder a gas that turns limewater milky is also produced. This is carbon dioxide, CO₂
.