The difference between a substance and a mixture is that a substance is one of a kind, a material of the same composition throughout, on the contrary, a mixture is one or more different substances brought together and mixed together without changing the nature of each single substance.
One way to test it is to take two substances like sand and table salt. They should each be in granular form and in adequate amount to mix. Neither substance has changed after mixing the two. Even though it may not be easy or convenient to accomplish, each substance could be separated out from the mixture.
When it comes to two substances in lump form, it would not be a mixture when one lump is positioned next to the other lump because there are not enough pieces to combine.
However, there could be a mixture of three substances, like sand, table salt and graphite powder and there could be a mixture with four substances, etc., ad infinitum.
Mixtures are of solid substances in general. On the other hand, one starts referring to solutions when liquids are involved. Gases can be a mixture like for example, air is a mixture with nitrogen, oxygen, argon, etc.
Answer: The rate of appearance of
is 
Explanation:
Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.

The rate in terms of reactants is given as negative as the concentration of reactants is decreasing with time whereas the rate in terms of products is given as positive as the concentration of products is increasing with time.
Rate in terms of disappearance of HBr =
= ![\frac{1d[H_2]}{dt}](https://tex.z-dn.net/?f=%5Cfrac%7B1d%5BH_2%5D%7D%7Bdt%7D)
Rate in terms of appearance of
= ![\frac{1d[Br_2]}{dt}](https://tex.z-dn.net/?f=%5Cfrac%7B1d%5BBr_2%5D%7D%7Bdt%7D)
![-\frac{1d[HBr]}{2dt}=\frac{d[H_2]}{dt}=\frac{d[Br_2]}{dt}](https://tex.z-dn.net/?f=-%5Cfrac%7B1d%5BHBr%5D%7D%7B2dt%7D%3D%5Cfrac%7Bd%5BH_2%5D%7D%7Bdt%7D%3D%5Cfrac%7Bd%5BBr_2%5D%7D%7Bdt%7D)
Given :
![-\frac{1d[HBr]}{dt}=0.140Ms^{-1}](https://tex.z-dn.net/?f=-%5Cfrac%7B1d%5BHBr%5D%7D%7Bdt%7D%3D0.140Ms%5E%7B-1%7D)
The rate of appearance of
;
![\frac{1d[Br_2]}{dt}=-\frac{1d[HBr]}{2dt}=\frac{1}{2}\times 0.140=0.0700Ms^{-1}](https://tex.z-dn.net/?f=%5Cfrac%7B1d%5BBr_2%5D%7D%7Bdt%7D%3D-%5Cfrac%7B1d%5BHBr%5D%7D%7B2dt%7D%3D%5Cfrac%7B1%7D%7B2%7D%5Ctimes%200.140%3D0.0700Ms%5E%7B-1%7D)
Thus rate of appearance of
is 
I’m not really sure but i think it’s 2.
Answer:
Electrolyte
Explanation:
A compound that conducts electricity when dissolved in water would most likely be classified as electrolyte.
The ionic compound in solid form do not conduct the electricity but when dissolve in water they separated into ions and have ability to conduct the electricity because of mobile ions that move freely and allow the charge to flow.
The ionic compounds are called electrolyte and electrolyte solution is formed when they dissolve in water.
For example when sodium chloride is placed into water it split into ions and conduct electricity because of mobile ions.
Chemical equation:
NaCl → Na⁺ + Cl⁻
Explanation:
(1) CuF2+Mg-------->MgF2+Cu
(2) 2Na+2H2O --------> 2NaOH+H2
(3) 2KBr+Cl2-------->2KCl+Br2