The answer is
Physical properties: Properties that do not change the chemical nature of matter
Chemical properties: Properties that do change tha chemical nature of matter
Examples of physical properties are: color, smell, freezing point, boiling point, melting point, infra-red spectrum, attraction (paramagnetic) or repulsion (diamagnetic) to magnets, opacity, viscosity and density. There are many more examples. Note that measuring each of these properties will not alter the basic nature of the substance.
Examples of chemical properties are: heat of combustion, reactivity with water, PH, and electromotive force.
When you add heat to a solid the particles gain energy and start to vibrate faster and faster.
When you add heat to a liquid the particles are given more energy and move faster and faster expanding the liquid.
The molarity of formic acid is 100 mM or 
. The dissociation reaction of formic acid is as follows:
The expression for dissociation constant of the reaction will be:
![K_{a}=\frac{[HCOO^{-}][H^{+}]}{[HCOOH]}](https://tex.z-dn.net/?f=K_%7Ba%7D%3D%5Cfrac%7B%5BHCOO%5E%7B-%7D%5D%5BH%5E%7B%2B%7D%5D%7D%7B%5BHCOOH%5D%7D)
Rearranging,
![[HCOO^{-}]=\frac{K_{a}[HCOOH]}{[H^{+}]}](https://tex.z-dn.net/?f=%5BHCOO%5E%7B-%7D%5D%3D%5Cfrac%7BK_%7Ba%7D%5BHCOOH%5D%7D%7B%5BH%5E%7B%2B%7D%5D%7D)
Here, pH of solution is 4.15 thus, concentration of hydrogen ion will be:
![[H^{+}]=10^{-pH}=10^{-4.15}=7.08\times 10^{-5}M](https://tex.z-dn.net/?f=%5BH%5E%7B%2B%7D%5D%3D10%5E%7B-pH%7D%3D10%5E%7B-4.15%7D%3D7.08%5Ctimes%2010%5E%7B-5%7DM)
Similarly, 
thus,
Putting the values,
![[HCOO^{-}]=\frac{(1.78\times 10^{-4}M)(100\times 10^{-3}M)}{(7.08\times 10^{-5}M}=0.2511 M](https://tex.z-dn.net/?f=%5BHCOO%5E%7B-%7D%5D%3D%5Cfrac%7B%281.78%5Ctimes%2010%5E%7B-4%7DM%29%28100%5Ctimes%2010%5E%7B-3%7DM%29%7D%7B%287.08%5Ctimes%2010%5E%7B-5%7DM%7D%3D0.2511%20M)
Therefore, the concentration of formate will be 0.2511 M.
Oxygen has 8 electrons. On the outer ring, it has 6 valance electrons. It need 2 more valance electrons to be stable.
There are 1.2 hr would this current have to be applied to plate out 7. 20 g of iron .
Calculation ,
Given ; Current ( I ) = 5. 68 A
In 
, the valancy of Fe is +2 .
2 moles of 
are required for the decomposition of 1 mole of Fe .
7. 20 g of Fe in moles = 7. 20 g /55.845 g/mol =0.12 mole
x moles of are required for the decomposition of 0.128 mole of Fe .
moles of are required = 0.256 moles
Charge on 1 mole of = 96500 C
Charge on 0.256 mole of = 24704 C
Current ( I )= Q/t
t =Q / I = 24704 C/5. 68 A = 4349 sec = 1.2 hr
Therefore , there are 1.2 hr would this current have to be applied to plate out 7. 20 g of iron .
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