Answer:
4 Fe + 3 O2 = 2 Fe2O3
Explanation:
In order to balance the equation, there should be equal number of iron atoms (Fe) and oxygen atoms (O2) in Iron(III) oxide (Fe2O3).
Since there are two atoms of Oxygen in 1 oxygen molecule and 3 atoms of Oxygen in 1 Iron Oxide, the least common multiples of the total oxygen atoms which would equal each other is 6 atoms of Oxygen. This results in 3 molecules of O2 and 2 molecules of Fe2O3.
In order to balance out the amount of iron in iron oxide, you must then calculate the total iron atoms in iron oxide; since there are 2 atoms of Fe in each molecule of Iron Oxide and there is 2 molecules of Fe2O3, the total is 2*2 = 4 atoms of iron, Fe.
In order to get 4 atoms of iron from molecules of Fe, you need 4 molecules of Fe, since each molecule contains 1 Fe.
If you go by the decimal there should be 5 significant digits because 0 is a trailing zero and matters since it comes after a decimal. however if you do
6.3590 x 10 ^7 = 63590000 then you would only have 4 significant digits because there is no longer a decimal to make the zero after the 9, significant.
Hope this helps!
Answer : The pH of a solution is, 7.28
Solution : Given,
Concentration of hydronium ion,
= 
pH : It is defined as the negative logarithm of hydronium ion concentration or hydrogen ion concentration.
![pH=-\log [H_3O^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH_3O%5E%2B%5D)
Now put the value of hydronium ion concentration in this expression, we get the pH of the solution.

Therefore, the pH of a solution is, 7.28
Answer:
when the substance is decrease
Explanation:
I am first assuming that you want the molarity of the acid. Use the formula

which is the titration formula. M is molarity (a is of acid and b is of base) and V is volume in mL (a is of acid and b is of base). Plugging in gives us

. Solving gives us