Question

1)For the following reaction, to get the rate of formation of SiO2, what must we multiply the rate of formation of H2O by? 2Si2H2+5O2⟶4SiO2+2H2O

1/2
2
−1/2
−2

2)For the following reaction, if O2 is used up at a rate of 4.42Mhr, what is the rate of consumption of NH3? 4NH3+5O2→NO+4H2O

=____moles per liter hour

3)All of the following are true about catalysts, EXCEPT: Select the correct answer below:

Catalysts can speed up the rate of a reaction.

They cause a system to reach equilibrium more quickly.

They change the value of an equilibrium constant.

They have no effect on equilibrium concentrations.

THANK YOU!!

Answer 1

2Si2H2+5O2⟶4SiO2+2H2O
The rate is represented as given below [in terms of product and reactants]
-1/2d[Si2H2]/dt = - 1/5d[O2]/dt = + 1/4d[SiO2]/dt = + 1/2d[O2]/dt
so to get rate of formation of SiO2,d[SiO2]/dt

d[SiO2]/dt= 4(1/2) d[O2]/dt = 2* d[O2]/dt
Multiplied by 2
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4NH3+5O2 ---->NO+4H2O The rate of this reaction represented as

-1/4d[NH3]/dt =-1/5d[O2]/dt = + 1*d[NO]/dt = + 1/4d[H2O]/dt
given
d[O2]/dt= 4.42 M Hr
we have
-1/4d[NH3]/dt =-1/5d[O2]/dt

d[NH3]/dt = 4/5*4.42 M Hr= 3.536 Moles/L-Hr
rate of consumption of NH3 =3.536 Moles/L-Hr
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2)
The only false statement about catalyst given is
They change the value of an equilibrium constant.
***************************************************
catalyst only speed up the chemical reaction in both direction. It can not alter equilibrium constant value

thanks!