AS Chemistry

I've been given a booklet of summer work and i haven't covered much of any of it before. There are various aspects I'm confused about particularly ionic equations. What are they and how do you write them? I haven't been given state symbols so I don't know which substances are aqueous. I don't really understand how you can tell if something is aqueous or not. One of the chemical reactions I have to write an ionic equation for is the reaction between nitric acid and potassium carbonate. Any help would be greatly appreciated!

There are a few rules you should know when determining whether something is aqueous or not. Typically, any compound containing alkali metals or halogens are aqueous. Compounds containing nitrate are almost always aqueous as well. The reaction between nitric acid and potassium carbonate looks like this:2HNO3 K2CO3 --> H2CO3 2KNO3(This reaction formed H2CO3, Otherwise known as carbonic acid. You should know that carbonic acid will usually split into H2O and CO2)So the full reaction is this: 2HNO3 K2CO3 --> H2O CO2 2KNO3we will then split apart any aqueous compounds and cancel them if their elements appear on both sides - remember alkali metals like potassium make aqueous compounds, as does nitrate: (just use the unbalanced equation for this)H NO3 K CO3 --> H2O CO2 K NO3 (Cancel out the nitrate and potassium because they appear in aqueous compounds on both sides)Your net ionic equation looks like this: (put the 2 back in from the balanced equation) 2H CO3 --> H2O CO2Hope this helped!

There are a few rules you should know when determining whether something is aqueous or not. Typically, any compound containing alkali metals or halogens are aqueous. Compounds containing nitrate are almost always aqueous as well. The reaction between nitric acid and potassium carbonate looks like this:2HNO3 K2CO3 --> H2CO3 2KNO3(This reaction formed H2CO3, Otherwise known as carbonic acid. You should know that carbonic acid will usually split into H2O and CO2)So the full reaction is this: 2HNO3 K2CO3 --> H2O CO2 2KNO3we will then split apart any aqueous compounds and cancel them if their elements appear on both sides - remember alkali metals like potassium make aqueous compounds, as does nitrate: (just use the unbalanced equation for this)H NO3 K CO3 --> H2O CO2 K NO3 (Cancel out the nitrate and potassium because they appear in aqueous compounds on both sides)Your net ionic equation looks like this: (put the 2 back in from the balanced equation) 2H CO3 --> H2O CO2Hope this helped!

Does the booklet give you any sort of information or is it purely questions? A good place to start to understand things is often chemguide.

Having said that, ionic equations are only really of any use for redox reactions, yet the example you give is an Acid-base reaction.

In terms of the example you give, you might (hopefully) know what happens when you react an acid and a carbonate and then be able to write out the whole equation.

You can usually assume that the ionic species involved are aqueous.

So, can you write the equation for reaction of acid and carbonate (you can leave out sate symbols for now) ?

edit: looks like the other poster has just given you the answer, but beware, what they've written has neglected charges on the ionic species!

second edit: also just seen you've asked this question in another thread, the reply there looks pretty helpful!

I've just tried another one. The reaction between magnesium and hydrochloric acid.

2HCl (aq) + Mg (s) ----> MgCl2 (aq) + H2 (g)

H(+) + Mg ---> Mg (2+) + H2

I'm not sure if the mg can be cancelled out or if other numbers are required in front of the symbols. Is this correct?

The second equation would be

2H⁺ + Mg ---> Mg²⁺ + H₂

But I'd say you seem to have the right idea!

This reaction is a redox reaction H+ is reduced (to H2), whilst Mg is oxidised (to Mg2+) so the Mg definitely can't be cancelled!

reduction and oxidation are ideas you'll get much more used to as you start AS

Thank you for your help!

No problem! In terms of including charges, you only include the charge for ionic species (so not for H2O or CO2) and you must make sure that the equations are balanced (same number of each element on each side and the same charge on each side of the equation!)

Feel free to ask me to check any more answers you come up with!

No problem! In terms of including charges, you only include the charge for ionic species (so not for H2O or CO2) and you must make sure that the equations are balanced (same number of each element on each side and the same charge on each side of the equation!)

Feel free to ask me to check any more answers you come up with!

CuO + H2SO4 ---> CuSO4 + H2O

CuO (s) + 2H(+)(aq) ---> Cu(2+)(aq) + H2O(l)

Seems like you've got the hang of it

Just for your info, the ions in each reaction that cancel out (ie dont change during the reaction) are called spectator ions

Seems like you've got the hang of it

Just for your info, the ions in each reaction that cancel out (ie dont change during the reaction) are called spectator ions

Zinc chloride can be prepared in the laboratory by the reaction between zinc and hydrogen chloride gas. An impure sample of zinc powder with a mass of 5.68g was reacted with hydrogen chloride gas until the reaction was complete. The zinc chloride produced had a mass of 10.7g. Calculate the percentage purity of the zinc metal.

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Do you know about moles and how to do calculations involving them?

Yep

So you need to go through the following questions

1. what is the reaction equation?
2. how many moles of Zinc Chloride do you make?
3. how many moles of Zinc would you need to make that much Zinc Chloride?
4. What mass of zinc would that correspond to?
5. Compare that mass with the mass of zinc powder, the difference is due to impurities

I'm not sure how to answer 3 and therefore the following steps

I'm not sure how to answer 3 and therefore the following steps