chem paper answers (1 Viewer)

[cloud edwards]

anyone got the answers to the art of smart 2017 chem paper?

 

[jazz519]

anyone got the answers to the art of smart 2017 chem paper?

Dont have answers but do you have any specific questions?

 

[cloud edwards]

Dont have answers but do you have any specific questions?

Yep, 11 (think it's ammonium chloride), 14 (think it's c), 20 (absolutely no idea) 23 a and b,

THANX

 

[jazz519]

11) For a basic salt remember we need a strong base and a weak acid to have reacted. Ammonium comes from ammonia (weak base) and chloride from HCl(strong acid), so in fact ammonium chloride would be an acidic salt.

The correct answer is A (pottasium hydroxide is a strong base (strong bases are from group 1 and 2) and citrate is from citric acid weak acid

 

[jazz519]

14) C is correct

 

[jazz519]

20)https://imgur.com/gallery/Ya7Q1

 

[jazz519]

23a) Avogadros law

 

[jazz519]

23b)https://imgur.com/gallery/kzZ8q

Sorry for multiple posts had to use my phone for the picture ones

 

[cloud edwards]

23b)https://imgur.com/gallery/kzZ8q

Sorry for multiple posts had to use my phone for the picture ones

No, THANK YOU, your'e a lifesaver!

 

[cloud edwards]

23a) Avogadros law

i didn't know yr 12 will still have avogrado's law
Thank you =)

 

[jazz519]

i didn't know yr 12 will still have avogrado's law
Thank you =)

Yeah I thought it was a little bit strange, then again though I have seen questions with avogadro's number as one of the steps in the calculation

 

[Snowflek]

20)https://imgur.com/gallery/Ya7Q1

Can you explain this again. Sorry, my maths is horrible. What do you convert the percentage into when you times it by 100 first? And then dividing it by 100?

 

[cloud edwards]

ONE more question; 21 b) Explain the need for a xataylst in the dehydration of ehtanol. I got the catalyst to conc sulfuric acid but i don't know the speciifc need

 

[cloud edwards]

ONE more question; 21 b) Explain the need for a xataylst in the dehydration of ehtanol. I got the catalyst to conc sulfuric acid but i don't know the speciifc need

all ican think of is catalysts lowers activation energy and speeds up reaction

 

[Snowflek]

ONE more question; 21 b) Explain the need for a xataylst in the dehydration of ehtanol. I got the catalyst to conc sulfuric acid but i don't know the speciifc need

Conc sulfuric acid is a dehydrating agent, so it will remove the water from ethanol.

 

[jazz519]

ONE more question; 21 b) Explain the need for a xataylst in the dehydration of ehtanol. I got the catalyst to conc sulfuric acid but i don't know the speciifc need

It's three marks so need to go into detail with stuff. I would define a catalyst. Explain why it speeds up reaction rate. Then state that in this reaction the catalyst acts a dehydrating agent. Lastly, linking back to benefits of using a catalyst as well such as saves money as you get a lower temperature needed due to more reactants being able to overcome the lower activation energy barrier.

 

[jazz519]

Can you explain this again. Sorry, my maths is horrible. What do you convert the percentage into when you times it by 100 first? And then dividing it by 100?

oh the dividing bit is converting from percentage to decimal and the 100mL is from the v/v bit

 

[jazz519]

Where did the *10^6 come from?

its parts per million (so the first fraction establishes a ratio of ozone to air) and the multiplication bit says how many ozone molecules there are in a million molecules of air

 

[jazz519]

If it was parts per billion then it would be x10^9

 

[zeee1999]

hey is question 5 for the multiple choice A??