Chemistry: Post your doubts here!

[Xaptor16]

You can try to create the 2 half equations

2HIO + 2H+ + 2e- --> I2 + 2H2O ------ (1)

HIO -+ 2H2O -> HIO3 + 4H+ + 4e- ------ (2)

Before combining the 2 equations, we need to make both equations have the same number of electrons
(2) x 2 + (1)

So ratio of I2 to HIO3 is 2: 1

Oxidation state of I in HIO, I2 and HIO3 is +1, 0 and +5 respectively.
Oxidation change from HIO to I2 is -2 (not -1 coz I-I)
Oxidation change from HIO to HIO3 is +4
View attachment 54137
Interchange the numbers, ie 2 for HIO3 and 4 for I2
2 : 4 ----> 1 : 2
n = 2 p = 1

thanks loadz!

 

[The Sarcastic Retard]

How is this possible? :/

 

[fantastic girl]

How is this possible? :/

i will tell u wat i think
they are asking abt RATE ryt?
removing ammonia will shift the equilibrium towards the forward reaction but rate wont increase i guess
check the rest of the options - all are the factors which affects the rate nd will definitely increase the rate of reaction
rate is like speed of the reaction and that is related to collisions nd all

 

[The Sarcastic Retard]

i will tell u wat i think
they are asking abt RATE ryt?
removing ammonia will shift the equilibrium towards the forward reaction but rate wont increase i guess
check the rest of the options - all are the factors which affects the rate nd will definitely increase the rate of reaction
rate is like speed of the reaction and that is related to collisions nd all

How can we know if the fwd rate is increase or not by the shifting of eq to fwd direction?
Check out C - My confusion.

 

[fantastic girl]

How can we know if the fwd rate is increase or not by the shifting of eq to fwd direction?
Check out C - My confusion.

ok till now i had the same problem like u....i used to be like its favoring forward reaction so rate of the reaction will be high
but most of the questions are just related to the factors which affect the rate
C- at first i wud say its wrong but see increasing temperature increases the kinetic energy of the molecules so more effective collisions which increases the rate of the reaction

removing ammonia will shift the equilibrium forward nd we will get more amount of ammonia but nothing will happen to rate...this is wat i understood :/

 

[Studydayandnight]

PLEASE HELP!

CORRECT ANSWER IS A.

How do we figure it out?

 

[The Sarcastic Retard]

ok till now i had the same problem like u....i used to be like its favoring forward reaction so rate of the reaction will be high
but most of the questions are just related to the factors which affect the rate
C- at first i wud say its wrong but see increasing temperature increases the kinetic energy of the molecules so more effective collisions which increases the rate of the reaction

removing ammonia will shift the equilibrium forward nd we will get more amount of ammonia but nothing will happen to rate...this is wat i understood :/

Thanks.

 

[Studydayandnight]

PLEASEEEE HELPPPPPPP

CORRECT ANSWER IS C.

 

[Metanoia]

i will tell u wat i think
they are asking abt RATE ryt?
removing ammonia will shift the equilibrium towards the forward reaction but rate wont increase i guess
check the rest of the options - all are the factors which affects the rate nd will definitely increase the rate of reaction
rate is like speed of the reaction and that is related to collisions nd all

That is correct, rate is dependent on temp, concentration and presence of catalyst.

Equilibrium is a ratio of the forward rate and backward rate.

In option D, the forward rate remains the same while the backward rate decreases.

 

[fantastic girl]

PLEASEEEE HELPPPPPPP

CORRECT ANSWER IS C.

write the whole reaction nd see
CH3Cl isnt possible ---- it wud form when methane reacts with Cl
B - has three carbon atoms which will form when propane reacts with Cl
C- its formed when two CH3CH2• combine
D- its not possible to get it in this reaction in the termination step

tell me if u still dont get......but iam sure if u write da reaction u will surely get it

 

[lara dalal]

How is this possible? :/

Pressure and temperature increase the rate of BOTH backward and forward reaction, its just that either the forward or backward is increased by a higher amount. In the case of haber process higher temp increases the backward reaction MORE than it increases the forward reaction, hence it shifts to the left hand side, but in general an increase in pressure/temp increases both forward and backward reaction.

 

[The Sarcastic Retard]

Pressure and temperature increase the rate of BOTH backward and forward reaction, its just that either the forward or backward is increased by a higher amount. In the case of haber process higher temp increases the backward reaction MORE than it increases the forward reaction, hence it shifts to the left hand side, but in general an increase in pressure/temp increases both forward and backward reaction.

concentration too yea?

 

[Studydayandnight]

How do we solve this?!!

Two glass vessels M and N are connected by a closed valve.

M contains helium at 20 °C at a pressure of 1 x 10^5 Pa. N has been evacuated, and has three times the volume of M. In an experiment, the valve is opened and the temperature of the whole apparatus is raised to 100 °C.

What is the final pressure in the system?

a. 3.18 x 10^4 Pa
b. 4.24 x 10^4 Pa
c.1.25 x 10^5 Pa
d.5.09 x 10^5 Pa

 

[lara dalal]

How do we solve this?!!

Two glass vessels M and N are connected by a closed valve.

M contains helium at 20 °C at a pressure of 1 x 10^5 Pa. N has been evacuated, and has three times the volume of M. In an experiment, the valve is opened and the temperature of the whole apparatus is raised to 100 °C.

What is the final pressure in the system?

a. 3.18 x 10^4 Pa
b. 4.24 x 10^4 Pa
c.1.25 x 10^5 Pa
d.5.09 x 10^5 Pa

what is the answer?

 

[Studydayandnight]

what is the answer?

It's A.

 

[Studydayandnight]

PLEASE HELPPPPPPPPPP

Correct answer is B.

 

[Studydayandnight]

How do we figure out the number of chiral centres present??
Correct answer is 6.

 

[Studydayandnight]

Omg, wth is this? -_-

Correct answer is D.

 

[lara dalal]

It's A.

Here is what I did, Idont know if there is another way of solving it or not. Anyhow this is how i did it.
First I found the volume of M in terms of n using PV=nRT (there is no way of actually finding the number of moles because they didnt give you the mass of Helium or its volume) Anyhow
Volume of M --> 1x10^5*V=n*8.31*(20+273)
V=0.024n
Now they told you that the volume of N is three times that of M hence Vol of N is 3*V i.e 3*0.024n = 0.073n
Now they asked for the final pressure which means the pressure of both the gasses M and N and they told you that the temp is 100 so what we do is first we find the TOTAL volume of both M and N which is 0.024n+0.073n= 0.097n
so to find the Total pressure just put in your values in the formula
P*0.097n=n*8.31*(100+273) (the n will cancel out)
P=3.18x10^4
BTW when you attempt solving it yourself use the exact values from the calculator, if you use my rounded off values you will get 3.19x10^4

 

[lara dalal]

PLEASE HELPPPPPPPPPP

Correct answer is B.

use m*c*delta T using m as your mass of water (because that is what is actually absorbing the heat)
200*4.18*(55-25)=25080J
Now convert that to KJ by dividing 25080 by 1000= 25.08KJ
To convert it to KJ/mol divide the 25.08 by the number of moles of the fuel used that is.0326
25.08/.0326=769