Biology; Chemistry; Physics: Post your doubts here!

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adilahmed900

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I am having trouble in this question. please help? and solve/explain it to me ??? I cant do it

Q1) The solubility of solid X at

30 degree C = 20g/100g of H2O.
70 degree C = 45g/100g of H2O

Part A) What mass of crystals would appear if 100g of H2O at 70 degree C saturated with solid X is cooled to 30 degree C. (Show your calculation).
Part B) 100g of water at 70 degree C contains 5g of solid X. What mass of crystals would appear if this solution is cooled to 30 degree C?
Part C) 100g of H2O at 30 degree C contains 20g of Solid X. The solution is kept aside for several days until the amount of water is to 25g. What mass of crystals would appear? Show your calculation.
 
Spidey21

Spidey21

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adilahmed900 said:
I am having trouble in this question. please help? and solve/explain it to me ??? I cant do it

Q1) The solubility of solid X at

30 degree C = 20g/100g of H2O.
70 degree C = 45g/100g of H2O

Part A) What mass of crystals would appear if 100g of H2O at 70 degree C saturated with solid X is cooled to 30 degree C. (Show your calculation).
Part B) 100g of water at 70 degree C contains 5g of solid X. What mass of crystals would appear if this solution is cooled to 30 degree C?
Part C) 100g of H2O at 30 degree C contains 20g of Solid X. The solution is kept aside for several days until the amount of water is to 25g. What mass of crystals would appear? Show your calculation.
Click to expand...

where did you get this question o_O
 
Mayedah

Mayedah

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adilahmed900 said:
I am having trouble in this question. please help? and solve/explain it to me ??? I cant do it

Q1) The solubility of solid X at

30 degree C = 20g/100g of H2O.
70 degree C = 45g/100g of H2O

Part A) What mass of crystals would appear if 100g of H2O at 70 degree C saturated with solid X is cooled to 30 degree C. (Show your calculation).
Part B) 100g of water at 70 degree C contains 5g of solid X. What mass of crystals would appear if this solution is cooled to 30 degree C?
Part C) 100g of H2O at 30 degree C contains 20g of Solid X. The solution is kept aside for several days until the amount of water is to 25g. What mass of crystals would appear? Show your calculation.
Click to expand...
Which past year question is this ?
 
Spidey21

Spidey21

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Spidey21 said:
where did you get this question o_O
Click to expand...

still my guess..

A => 45-20 =25g of crystals would appear!! :D

B=> no mass will appear...:)

C=> 20/100= 5/25...... 20-5= 15g of crystals would appear...:D

I might be wrong just one thing...the crystals will be made from the particles that are no more with the water right??? :D
 
khizer shahab

khizer shahab

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Spidey21 said:
still my guess..

A => 45-20 =25g of crystals would appear!! :D

B=> no mass will appear...:)

C=> 20/100= 5/25...... 20-5= 15g of crystals would appear...:D

I might be wrong just one thing...the crystals will be made from the particles that are no more with the water right??? :D
Click to expand...


agree with you with first two parts!!
 
khizer shahab

khizer shahab

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adilahmed900 said:
I am having trouble in this question. please help? and solve/explain it to me ??? I cant do it

Q1) The solubility of solid X at

30 degree C = 20g/100g of H2O.
70 degree C = 45g/100g of H2O

Part A) What mass of crystals would appear if 100g of H2O at 70 degree C saturated with solid X is cooled to 30 degree C. (Show your calculation).
Part B) 100g of water at 70 degree C contains 5g of solid X. What mass of crystals would appear if this solution is cooled to 30 degree C?
Part C) 100g of H2O at 30 degree C contains 20g of Solid X. The solution is kept aside for several days until the amount of water is to 25g. What mass of crystals would appear? Show your calculation.
Click to expand...

part c) unitary method
100g h2O---------------------20g solid
25g h2O---------------------- x
cross multiply
(20*25)/1oo => 5g:)(y)
 
Spidey21

Spidey21

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khizer shahab said:
part c) unitary method
100g h2O---------------------20g solid
25g h2O---------------------- x
cross multiply
(20*25)/1oo => 5g:)(y)
Click to expand...

well thats the mass of crystals still in the water..the mass of 15g crystals will be given off and they will be produced thats why i said 15g...:)
 
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