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[The Godfather]

Given the following enthalpy changes, I2(g) + 3Cl2(g) → 2ICl3(s) ∆Ho = –214kJ mol–1 I2(s) → I2(g) ∆Ho = +38kJ mol–1 What is the standard enthalpy change of formation of iodine trichloride, ICl3(s)?

 

[awesomaholic101]

0.96g of oxygen gas is contained in a glass vessel of volume 7000 cm3 at a temperature of 30°C.
What is the pressure in the vessel?
A 1.1 kPa
B 2.1 kPa
C 10.8 kPa
D 21.6 kPa

Ans: C, right?

pV = nRT
p*7000*10^-6 = (0.96/32) * 8.31 * (30+273)
Therefore, p = 10791 Pa = 10.8 kPa

 

[awesomaholic101]

The Boltzmann distribution shows the number of molecules having a particular kinetic energy at
constant temperature.

number of gas
molecules having
a given energy
0
0
kinetic energy
N
L M
Ea
If the temperature is decreased by 10 °C, what happens to the size of the areas labelled L, M and
N?

L M N
A decreases decreases decreases
B decreases increases decreases
C increases decreases decreases
D increases decreases increases

Please give the link to the question, maybe? I can't understand what you have posted.

 

[Akshajistari]

Hi! Where can I find solved Physics MCQ Papers? (9702)

 

[awesomaholic101]

Hi! Where can I find solved Physics MCQ Papers? (9702)

http://physics-ref.blogspot.in/

 

[Akshajistari]

Thank you ! awesomaholic101

 

[awesomaholic101]

Thank you ! awesomaholic101

no problem

 

[Symzyx]

17 A piece of rock has a mass of 2.00g. It contains calcium carbonate, but no other basic substances. It neutralises exactly 36.0cm3 of 0.500moldm–3 hydrochloric acid. What is the percentage of calcium carbonate in the 2.00g piece of rock?
A 22.5% B 45.0% C 72.0% D 90.1%

An explanation would be much appreciated!

 

[krishnapatelzz]

17 A piece of rock has a mass of 2.00g. It contains calcium carbonate, but no other basic substances. It neutralises exactly 36.0cm3 of 0.500moldm–3 hydrochloric acid. What is the percentage of calcium carbonate in the 2.00g piece of rock?
A 22.5% B 45.0% C 72.0% D 90.1%

An explanation would be much appreciated!

answer is D , first write the balanced equation for the reaction that is CaCO3 + 2HCl -> CaCl2 + CO2 + H2O , then calculate the moles of HCL that is concentration x volume = 0.5 x 0.036 = 0.018 . 2 moles of HCl are needed to neutralise 1 mole of CaCO3 , so the moles of CaCO3 is 0.018/2 = 0.009 . as now you have moles and molar mass of CaCO3 you can find the mass of CaCO3 that reacted from the rock . so the mass of CaCO3 reacted = 100 x 0.009= 0.9 .to find the percentage of calcium carbonate in 2.00g rock , mass of CaCO3 reacted / mass of rock x 100 = 0.9/2.0 x 100 = 45.0%

 

[Symzyx]

A 0.005 mol sample of anhydrous calcium carbonate was completely thermally decomposed to give 100cm3 of gas measured at a certain temperature and pressure. In a separate experiment carried out at the same temperature and pressure, a 0.005mol sample of anhydrous calcium nitrate was completely thermally decomposed. The volume of gaseous products was measured. What total volume of gaseous products was produced from the calcium nitrate?

A 50cm3 B 100cm3 C 200cm3 D 250cm3

 

[ErosKuikel]

Guys! I need help with this question with an explanation!!
Mj 2007 p1 qn 18

 

[Dukula Jayasinghe]

This place is awesome! Great work guyzzzzzzzzzzzzzzzzzz

 

[toobariaz]

Q18 For which equation does the enthalpy change correspond to the enthalpy change of atomization of iodine?
A 1⁄2 I2(s) → I(s)
B 1⁄2 I2(s) → I(g)
C I2(g) → 2I(g)
D I2(s) → 2I(g)

 

[Asim Shah]

topical past papers please