Biology; Chemistry; Physics: Post your doubts here!

[Bhaijan]

Hi guys, I have a very important question on Chemistry. In 5070_s08_qp_1 Q7, which is about chromatography, the Rf value given does not make any sense. Please analyse it.
my chem book says Rf value is = the distance travelled by sample/distance travelled by solvent

 

[funky brat]

Hi guys, I have a very important question on Chemistry. In 5070_s08_qp_1 Q7, which is about chromatography, the Rf value given does not make any sense. Please analyse it.
my chem book says Rf value is = the distance travelled by sample/distance travelled by solvent

Post screenshot of paper, maybe.

 

[funky brat]

Calcium sulphate is an insoluble salt so it is made my ionic precipitation not by titration.

And calcium carbonate is insoluble. (Forgot to mention )

 

[exploded diper]

And calcium sulphate is insoluble. (Forgot to mention )

dude check agn.. u forgot tht u did mention tht...

 

[exploded diper]

Hi guys, I have a very important question on Chemistry. In 5070_s08_qp_1 Q7, which is about chromatography, the Rf value given does not make any sense. Please analyse it.
my chem book says Rf value is = the distance travelled by sample/distance travelled by solvent

becux the starting distance has to be same.........so the ans is b........

 

[funky brat]

dude check agn.. u forgot tht u did mention tht...

Edited*

 

[Bhaijan]

I uploaded the pic.

 

[Awesome12]

With a detailed explanation

 

[asadalam]

With a detailed explanation
View attachment 39272 View attachment 39273

18.A cuz the rate is fastest(the big curves actually show more time like when we take a deep breath)
14.This is a tricky graph that i cant seem to grasp,any explanation on the various phases?

 

[Awesome12]

18.A cuz the rate is fastest(the big curves actually show more time like when we take a deep breath)
14.This is a tricky graph that i cant seem to grasp,any explanation on the various phases?

About 14, yeah me too
The pressure in the aorta and atrium are increasing, but it is decreasing in the ventricles. However, both valves are closed

 

[Awesome12]

With a detailed explanation
View attachment 39272 View attachment 39273

funky brat

 

[funky brat]

With a detailed explanation
View attachment 39272 View attachment 39273

He explained the first mcq right.
For the second see, the pressure in the left atrium is constant which means the blood is in the left ventricle ready to leave through the aorta. Now see when blood is pushed out through any chamber of heart, it contracts and the pressure in it increases. But at point X, the pressure in both is decreasing which means blood has flown out and now semi lunar valve has been closed to prevent back flow of blood. Also when any chamber relax it can be filled up with blood, so when left atrium is relaxing the bicuspid valve needs to be closed to prevent blood from flowing backwards. So the answer is A. Right?

 

[Faizan Muhammmad]

He explained the first mcq right.
For the second see, the pressure in the left atrium is constant which means the blood is in the left ventricle ready to leave through the aorta. Now see when blood is pushed out through any chamber of heart, it contracts and the pressure in it increases. But at point X, the pressure in both is decreasing which means blood has flown out and now semi lunar valve has been closed to prevent back flow of blood. Also when any chamber relax it can be filled up with blood, so when left atrium is relaxing the bicuspid valve needs to be closed to prevent blood from flowing backwards. So the answer is A. Right?

Simpler:
First see the line is cutting the curves in middle not in a single peak
so either both open or both close
the pressure in left ventricle is decreasing so it has just contracted, meaning semilunar closed and bicuspid too

 

[Awesome12]

He explained the first mcq right.
For the second see, the pressure in the left atrium is constant which means the blood is in the left ventricle ready to leave through the aorta. Now see when blood is pushed out through any chamber of heart, it contracts and the pressure in it increases. But at point X, the pressure in both is decreasing which means blood has flown out and now semi lunar valve has been closed to prevent back flow of blood. Also when any chamber relax it can be filled up with blood, so when left atrium is relaxing the bicuspid valve needs to be closed to prevent blood from flowing backwards. So the answer is A. Right?

Thanks but when the bicuspid valves closes, then no blood will enter the ventricles. Like this when the ventricles contract, there won't be any blood in the ventricles which is not possible

 

[funky brat]

Thanks but when the bicuspid valves closes, then no blood will enter the ventricles. Like this when the ventricles contract, there won't be any blood in the ventricles which is not possible

Is the answer right?
What? :O

 

[funky brat]

Thanks but when the bicuspid valves closes, then no blood will enter the ventricles. Like this when the ventricles contract, there won't be any blood in the ventricles which is not possible

When bicuspid valve closes no blood will enter the left atrium.

 

[Awesome12]

Is the answer right?
What? :O

yup

 

[funky brat]

Simpler:
First see the line is cutting the curves in middle not in a single peak
so either both open or both close
the pressure in left ventricle is decreasing so it has just contracted, meaning semilunar closed and bicuspid too

Very smart indeed.

 

[Awesome12]

When bicuspid valve closes no blood will enter the left atrium.

Bicuspid links the atrium to the ventricle. Its like a dam. You build a wall to separate water behind the wall (A) and ahead of the wall (B). It the wall is present, then the water cannot flow from (A) to (B), but water from behind can enter A

 

[funky brat]

Bicuspid links the atrium to the ventricle. Its like a dam. You build a wall to separate water behind the wall (A) and ahead of the wall (B). It the wall is present, then the water cannot flow from (A) to (B), but water from behind can enter A

Yeah, but to make it simple just assume one thing is happening at a time.