Answer: 
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
Thus in the reactants, there are 2 atoms of hydrogen and 2 atoms of iodine .Thus there has to be 2 atoms of hydrogen and 2 atoms of iodine in the product as well. Thus a coefficient of 2 is placed in front of HI.
The balanced chemical reaction is:

<span>Fe(NO3)2
The NO3 part is a poly-atomic ion with total charge -1.
This is because Fe has a +2 charge and two NO3's with a -1 charge will balance out to 0.
Most often we just make the assumption that Oxygen has a -2 oxidation number because it is very electro-negative.
So to find N, we just need an oxidation number that balances out with 3(-2) to get -1 (the total charge of the ion)</span>
A solution with a pH of 6.52 has a hydronium ion concentration of 3.02x10-7 mol/L and a hydroxide ion concentration of 3.31x10-8 mol/L.
The hydronium ion concentration of a solution can be calculated from pH by using
. For a pH of 6.52, hydronium ion concentration is 3.02x10-7 mol/L.
The concentration of hydroxide ions can be determined by identifying the value of pOH. The sum of pOH and pH is equal to 14, which is based on the negative logarithm of the ion-product constant of water. At a pH of 6.52, pOH is equal to 7.48.
The relationship between pOH and hydroxide ion concentration is the same as the relationship between pH and hydronium ion concentration. With this, the hydroxide ion concentration at pOH of 7.48 is
or 3.31x10-8 mol/L.
For more information regarding pH and pOH, please refer to the link brainly.com/question/13557815.
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The relative molecular mass of acid A : 50 g/mol
<h3>Further explanation</h3>
Given
40.0 cm³(40 ml) of 0.2M sodium hydroxide
0.2g of a dibasic acid
Required
the relative molecular mass of acid A
Solution
Titration formula
M₁V₁n₁=M₂V₂n₂
n=acid/base valence(number of H⁺/OH⁻)
NaOH ⇒ n = 1
Dibasic acid = diprotic acid (such as H₂SO₄)⇒ n = 2
mol = M x V
Input the value in the formula :(1 = NaOH, 2=dibasic acid)
0.2 x 40 x 1 = M₂ x V₂ x 2
M₂ x V₂ = 4 mlmol = 4.10⁻³ mol ⇒ mol of Acid A
The relative molecular mass of acid A (M) :

Answer:
your answer should be the bottom
sorry if im wrong
Explanation: