# Chemistry and Physics questions IMMEDIATE HELP

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Thread starter 3 months ago
#1
i must answer these questions as soon as possible as they may cost me a grade. It would be much appreciated if you could help
Sulfuric acid can be reacted with potassium chloride to produce potassium sulfate, which is an important ingredient in some fertilizers. The Balanced equation below shows this reaction:
H2SO4 + 2KCl = K2SO4 + 2HCL
Calculate the mass of potassium chloride needed to produce 100g of potassium sulfate.
Relative Formula Masses (Mr): KCl = 74.5. K2SO4 = 174

3) The diesel fraction of crude oil contains C16H34 molecules.
These molecules are cracked for economic reasons.
Explain this statement. Include a balanced equation in your answer.

4) A coin is dropped from the top of a building. It falls 300m to the ground. Calculate the speed of the coin just before it hits the ground. State any assumptions you make. Give your answer to 3 significant figures.
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3 months ago
#2
for the physics one use v^2=2as so use root 2as and that is 76.72 and the assumption is negligible air resistance or no air resistance
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3 months ago
#3
and the chemistry first one is 85.63 grams
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Thread starter 3 months ago
#4
(Original post by Sterlingn1)
and the chemistry first one is 85.63 grams
Thank You so much! How did you get the answer of 85.64 grams?
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3 months ago
#5
(Original post by Sterlingn1)
and the chemistry first one is 85.63 grams
The general philosophy of TSR is to help people work their own way through problems, rather than just doing their work for them.

Giving people answers is a terrible way for them to learn.
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3 months ago
#6

Here’s a basic method for the first question. This does give the answer said above. Have a go and see what you get.
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3 months ago
#7
For the diesel fraction of crude oil you need to consider supply and demand. Often, smaller chain hydrocarbons are in lowers supply and higher demand, so can be sold for a greater price. I think this is the main consideration.
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3 months ago
#8

This is the information in the falling coin question presented in a way which should help. There are definitely assumptions made in saying that acceleration is 9.81 ms-2 and constant. There may be an assumption in saying that u is 0 ms-1.
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