Chemistry: Post your doubts here!

[♣♠ Magnanimous ♣♠]

Would be glad if anyone out there could help me with these questions.
( I need simple explanations)

Which gas is likely to deviate most from ideal gas behaviour?
A HCl B He C CH4 D N2

The answer is A NOT C .....Why?



Flask X contains 5 dm3 of helium at 12 kPa pressure and flask Y contains 10 dm3 of neon at 6 kPa pressure.
If the flasks are connected at constant temperature, what is the final pressure?(The answer is A)
A 8 kPa B 9 kPa C 10 kPa D 11 kPa

I don't get this!!

Q9 Use of the Data Booklet is relevant to this question.
The volume of a sample of ammonia is measured at a temperature of 60 °C and a pressure of 103 kPa. The volume measured is 5.37 × 10–3 m3.
What is the mass of the sample of ammonia, given to two significant figures?
A 0.00019 g B 0.0034 g C 0.19 g D 3.4 g

No matter how many times I try it my answer is None of the above!


Section B
An ideal gas obeys the gas laws under all conditions of temperature and pressure.
Which of the following are true for an ideal gas?
1 The molecules have negligible volume.
2 There are no forces of attraction between molecules.
3 The molecules have an average kinetic energy which is proportional to its absolute
temperature.

Third point states
The molecules have an average kinetic energy which is proportional to its absolute
temperature.
The kinetic energy and temperature are related and as one increases so does the other....is this what it says ?

When a sample of a gas is compressed at constant temperature from 1500 kPa to 6000 kPa, its volume changes from 76.0 cm3 to 20.5 cm3.
Which statements are possible explanations for this behaviour?
1 The gas behaves non-ideally.
2 The gas partially liquefies.
3 Gas is adsorbed on to the vessel walls.

Second point;2 The gas partially liquefies.
Why isn't this correct?

1) Umm, you just read the topic "The kinetic theory of gases"(on page 99 of coursebook written by Roger Norris). Do you observe that all points are related to GASES while HCl IS A LIQUID. So it can be clearly said that IT IS THE ONE WHICH MOST DEVIATE FROM IDEAL GAS BEHAVIOUR.
You got na?

 

[♣♠ Magnanimous ♣♠]

Would be glad if anyone out there could help me with these questions.
( I need simple explanations)

Which gas is likely to deviate most from ideal gas behaviour?
A HCl B He C CH4 D N2

The answer is A NOT C .....Why?



Flask X contains 5 dm3 of helium at 12 kPa pressure and flask Y contains 10 dm3 of neon at 6 kPa pressure.
If the flasks are connected at constant temperature, what is the final pressure?(The answer is A)
A 8 kPa B 9 kPa C 10 kPa D 11 kPa

I don't get this!!

Q9 Use of the Data Booklet is relevant to this question.
The volume of a sample of ammonia is measured at a temperature of 60 °C and a pressure of 103 kPa. The volume measured is 5.37 × 10–3 m3.
What is the mass of the sample of ammonia, given to two significant figures?
A 0.00019 g B 0.0034 g C 0.19 g D 3.4 g

No matter how many times I try it my answer is None of the above!


Section B
An ideal gas obeys the gas laws under all conditions of temperature and pressure.
Which of the following are true for an ideal gas?
1 The molecules have negligible volume.
2 There are no forces of attraction between molecules.
3 The molecules have an average kinetic energy which is proportional to its absolute
temperature.

Third point states
The molecules have an average kinetic energy which is proportional to its absolute
temperature.
The kinetic energy and temperature are related and as one increases so does the other....is this what it says ?

When a sample of a gas is compressed at constant temperature from 1500 kPa to 6000 kPa, its volume changes from 76.0 cm3 to 20.5 cm3.
Which statements are possible explanations for this behaviour?
1 The gas behaves non-ideally.
2 The gas partially liquefies.
3 Gas is adsorbed on to the vessel walls.

Second point;2 The gas partially liquefies.
Why isn't this correct?

2) Of that Flask X and Y wala --->
let P1V1 refer to the He, and P2V2 refer to the Ne, and P3V3 refer to the mixed gases

P*V = constant in all cases

P1V1 + P2V2 = P3V3
12*5 + 6*10 = P3*15
60 + 60 = P3*15
P3 = 120/15
P3 = 8kPa

Final pressure = 8kPa.
I hope now no confusion in this one right?

 

[♣♠ Magnanimous ♣♠]

Would be glad if anyone out there could help me with these questions.
( I need simple explanations)

Which gas is likely to deviate most from ideal gas behaviour?
A HCl B He C CH4 D N2

The answer is A NOT C .....Why?



Flask X contains 5 dm3 of helium at 12 kPa pressure and flask Y contains 10 dm3 of neon at 6 kPa pressure.
If the flasks are connected at constant temperature, what is the final pressure?(The answer is A)
A 8 kPa B 9 kPa C 10 kPa D 11 kPa

I don't get this!!

Q9 Use of the Data Booklet is relevant to this question.
The volume of a sample of ammonia is measured at a temperature of 60 °C and a pressure of 103 kPa. The volume measured is 5.37 × 10–3 m3.
What is the mass of the sample of ammonia, given to two significant figures?
A 0.00019 g B 0.0034 g C 0.19 g D 3.4 g

No matter how many times I try it my answer is None of the above!


Section B
An ideal gas obeys the gas laws under all conditions of temperature and pressure.
Which of the following are true for an ideal gas?
1 The molecules have negligible volume.
2 There are no forces of attraction between molecules.
3 The molecules have an average kinetic energy which is proportional to its absolute
temperature.

Third point states
The molecules have an average kinetic energy which is proportional to its absolute
temperature.
The kinetic energy and temperature are related and as one increases so does the other....is this what it says ?

When a sample of a gas is compressed at constant temperature from 1500 kPa to 6000 kPa, its volume changes from 76.0 cm3 to 20.5 cm3.
Which statements are possible explanations for this behaviour?
1 The gas behaves non-ideally.
2 The gas partially liquefies.
3 Gas is adsorbed on to the vessel walls.

Second point;2 The gas partially liquefies.
Why isn't this correct?

9)Well I am getting 3397.8 now convert it into significant figures you will get answer
Either it B or D as answer
Am I right?

 

[♣♠ Magnanimous ♣♠]

9) (1) here edit 5730 as 5.37 dm3
(2) (3)

 

[♣♠ Magnanimous ♣♠]

Would be glad if anyone out there could help me with these questions.
( I need simple explanations)

Which gas is likely to deviate most from ideal gas behaviour?
A HCl B He C CH4 D N2

The answer is A NOT C .....Why?



Flask X contains 5 dm3 of helium at 12 kPa pressure and flask Y contains 10 dm3 of neon at 6 kPa pressure.
If the flasks are connected at constant temperature, what is the final pressure?(The answer is A)
A 8 kPa B 9 kPa C 10 kPa D 11 kPa

I don't get this!!

Q9 Use of the Data Booklet is relevant to this question.
The volume of a sample of ammonia is measured at a temperature of 60 °C and a pressure of 103 kPa. The volume measured is 5.37 × 10–3 m3.
What is the mass of the sample of ammonia, given to two significant figures?
A 0.00019 g B 0.0034 g C 0.19 g D 3.4 g

No matter how many times I try it my answer is None of the above!


Section B
An ideal gas obeys the gas laws under all conditions of temperature and pressure.
Which of the following are true for an ideal gas?
1 The molecules have negligible volume.
2 There are no forces of attraction between molecules.
3 The molecules have an average kinetic energy which is proportional to its absolute
temperature.

Third point states
The molecules have an average kinetic energy which is proportional to its absolute
temperature.
The kinetic energy and temperature are related and as one increases so does the other....is this what it says ?

When a sample of a gas is compressed at constant temperature from 1500 kPa to 6000 kPa, its volume changes from 76.0 cm3 to 20.5 cm3.
Which statements are possible explanations for this behaviour?
1 The gas behaves non-ideally.
2 The gas partially liquefies.
3 Gas is adsorbed on to the vessel walls.

Second point;2 The gas partially liquefies.
Why isn't this correct?

Section B
1) See page 76. Topic "The kinetic theory of gases"
In that last point ---> THE TEMPERATURE OF THE GAS IS RELATED TO THE AVERAGE KINETIC ENERGY OF THE MOLECULES

It means that third point is also correct and the answer is A
The sentence( I wrote above) clearly says everything and also clears your doubt.

I hope you got it. If any doubt quote this again

 

[♣♠ Magnanimous ♣♠]

Would be glad if anyone out there could help me with these questions.
( I need simple explanations)

Which gas is likely to deviate most from ideal gas behaviour?
A HCl B He C CH4 D N2

The answer is A NOT C .....Why?



Flask X contains 5 dm3 of helium at 12 kPa pressure and flask Y contains 10 dm3 of neon at 6 kPa pressure.
If the flasks are connected at constant temperature, what is the final pressure?(The answer is A)
A 8 kPa B 9 kPa C 10 kPa D 11 kPa

I don't get this!!

Q9 Use of the Data Booklet is relevant to this question.
The volume of a sample of ammonia is measured at a temperature of 60 °C and a pressure of 103 kPa. The volume measured is 5.37 × 10–3 m3.
What is the mass of the sample of ammonia, given to two significant figures?
A 0.00019 g B 0.0034 g C 0.19 g D 3.4 g

No matter how many times I try it my answer is None of the above!


Section B
An ideal gas obeys the gas laws under all conditions of temperature and pressure.
Which of the following are true for an ideal gas?
1 The molecules have negligible volume.
2 There are no forces of attraction between molecules.
3 The molecules have an average kinetic energy which is proportional to its absolute
temperature.

Third point states
The molecules have an average kinetic energy which is proportional to its absolute
temperature.
The kinetic energy and temperature are related and as one increases so does the other....is this what it says ?

When a sample of a gas is compressed at constant temperature from 1500 kPa to 6000 kPa, its volume changes from 76.0 cm3 to 20.5 cm3.
Which statements are possible explanations for this behaviour?
1 The gas behaves non-ideally.
2 The gas partially liquefies.
3 Gas is adsorbed on to the vessel walls.

Second point;2 The gas partially liquefies.
Why isn't this correct?

Section B
2) Of liquefies --->
Well I don't know the exact reason so I think you should remember it
Sorry in this question I was not able to help you

 

[Bhargav Poudel]

2013 O/N Paper 13 Q. 3,14,17,22,28,39. Anybody please?

 

[♣♠ Magnanimous ♣♠]

2013 O/N Paper 13 Q. 3,14,17,22,28,39. Anybody please?

3)You use 10×0.30 = 3 moles of Tl^+ for every 20×0.10 = 2 moles of VO3^-. Every Tl^+ ion loses 2 electrons, so for every equivalent of Tl^+, you get 2(3) = 6 electrons to be taken up by the V atoms.

In VO3^-, V is present as +5. 6 electrons are taken up by 2 equivalents, so 1 equivalent will take up 3 electrons. This leaves you with +5 - 3 = +2.

 

[♣♠ Magnanimous ♣♠]

14)

2013 O/N Paper 13 Q. 3,14,17,22,28,39. Anybody please?

The answer is B. We can get hint as the "chalky" means something related to carbonate and also the carbonates are insoluble so answer is B

 

[♣♠ Magnanimous ♣♠]

2013 O/N Paper 13 Q. 3,14,17,22,28,39. Anybody please?

17) MgO is basic oxides and most metal hydroxides are insoluble, an alkali added to a solution of a metal salt will precipitate an insoluble metal hydroxide. So answer is B

 

[Bhargav Poudel]

1) Umm, you just read the topic "The kinetic theory of gases"(on page 99 of coursebook written by Roger Norris). Do you observe that all points are related to GASES while HCl IS A LIQUID. So it can be clearly said that IT IS THE ONE WHICH MOST DEVIATE FROM IDEAL GAS BEHAVIOUR.
You got na?

HCl can be gas too!?

 

[♣♠ Magnanimous ♣♠]

HCl can be gas too!?

But as HCl is a polar compound it remains as liquid and due to high electronegativity it deviates most from ideal behaviour

 

[qdkhan]

When asked to write about how temperature affects rate, do we mention the Boltzmann theory?
Can we just not write that kinetic energy increases so collision frequency increases?
please mention all d details dis answer should state..

 

[♣♠ Magnanimous ♣♠]

When asked to write about how temperature affects rate, do we mention the Boltzmann theory?
Can we just not write that kinetic energy increases so collision frequency increases?
please mention all d details dis answer should state..

You can write --> As temperature is increased more particles will have energy to react which leads to increases in successful collision between particles resulting in increase in rate of reaction.

 

[The Chill Master]

9) (1)View attachment 49883 here edit 5730 as 5.37 dm3
(2)View attachment 49884 (3)View attachment 49885

dude u shld take voulme in m^3 not dm^3 our tchr told us if u take it in that u get the answer as d

 

[The Chill Master]

Section B
2) Of liquefies --->
Well I don't know the exact reason so I think you should remember it
Sorry in this question I was not able to help you

1 and 2 are correct

 

[fatimarehman]

I want to ask about practicals in practicals then how much time do we actually need to prepare for biology and science practicals as I have practiced practicals for two months only 8 classes. So I am worried as i want to give as exam. My theory and mcqs skills are good. But I have been told that the student who gets B grade in practical gets an overall B in as exam. Is that true?

 

[The Chill Master]

I want to ask about practicals in practicals then how much time do we actually need to prepare for biology and science practicals as I have practiced practicals for two months only 8 classes. So I am worried as i want to give as exam. My theory and mcqs skills are good. But I have been told that the student who gets B grade in practical gets an overall B in as exam. Is that true?

well dont know about bio as well as anything about that grade thingy but i think 8 practicals r less u shld ask for more practise we hv done so far only titration and salt analysis and hv dun it like more than 6 times so we are rele gud at it but if u think u cn give it a shot at pracs and can score gud then it wld be fi9.

 

[♣♠ Magnanimous ♣♠]

dude u shld take voulme in m^3 not dm^3 our tchr told us if u take it in that u get the answer as d

Means overall the calculation was correct.

 

[The Chill Master]

Means overall the calculation was correct.

yep