J.J. Thomson discovered the electron 1897
Answer:

Explanation:
Hello,
In this case, the undergoing chemical reaction is:

Thus, in terms of pressures, the rate becomes:

Thus, the rate of change for the partial pressure of ammonia turns out:
![r_{NH_3}=2*(-r_{N_2H_4})\\r_{NH_3}=2*[-(-70torr/h)]\\r_{NH_3}=140torr/h](https://tex.z-dn.net/?f=r_%7BNH_3%7D%3D2%2A%28-r_%7BN_2H_4%7D%29%5C%5Cr_%7BNH_3%7D%3D2%2A%5B-%28-70torr%2Fh%29%5D%5C%5Cr_%7BNH_3%7D%3D140torr%2Fh)
The rate of decrease of partial pressure of urea is taken negative as it is a reactant whereas ammonia a product which has 2 as its stoichiometric coefficient.
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Answer: The correct answer is crude oil is a mixture of many organic compounds that need to be isolated to be used.
Explanation:
Crude oil is a naturally occurring petroleum product which is unrefined. It consists of various hydrocarbon deposits and organic compounds.
The refining of crude oil is important because it yield some important compounds that can be used in various purposes.
The refining of crude oil produces products such as gasoline, petrol, diesel and various other forms of petrochemicals which can be used on daily basis.
Hence, the correct statement is crude oil is a mixture of many organic compounds that need to be isolated to be used.
well excuse the "s" at the end