The rate of the reaction is measurable quantity that refers to the amount or how much is are chemical substances reagents used up or converted into the product over some period of time.
Rate = change in the amount/time.
This can indirectly be observed through many ways, such as the volume of gas given off if the byproduct is a gas being produced, the colour of the solution etc.
Answer:
The answer will be :
In year 1869
Russian scientist named Dmitri Mendeleev
Chart called Mendeeleves periodic table
increasing atomic masses
physical and chemical properties.
Hope this Helps
Best of luck !!
Answer:

Explanation:
SO in order to calculate the specific latent heat of fusion, you need to remember the formula:

Where
representes the specific latent heart of fusion.
represents the heat energy added, usually represented in kJ
represents the mass of the object, in kg.
Now that we have our formula we just have to put our values into the formula:



SO our answer would be 
Im not sure but i think its 350. I really hope im right
Answer: 8 moles
Explanation:
Nc2H6= 4 mol
2C2H6 + 7O2 → 4CO2+6H2O
CO2=4/2⋅4
NCO2= 8 moles
( I write this on paper so the letters and format might be confusing) sorry!!