The atomic number of iodine (53) tells us that a neutral iodine atom contains 53 protons in its nucleus and 53 electrons outside its nucleus. Because the sum of the numbers of protons and neutrons equals the mass number, 127, the number of neutrons is 74 (127 − 53 = 74).... i think....
N2 + CaC2 = CaNCN + C
<span>As you can see, 1 mol of N2 can react completely with 1 mol of CaC2 and 1 mol of CaNCN will be obtained </span>
<span>It means 5 mol of N2 can react completely with 5 mol of CaC2 and 5 mol of CaNCN will be obtained </span>
<span>So, there are 7.5 - 5 = 2.5 odd mole of CaC2 after the reaction </span>
<span>And the mass of obtained CaNCN is </span>
<span>m = n*M = 5*80 = 400g</span>
Answer:
28.58 g of NaOH
Explanation:
The question is incomplete. The missing part is:
<em>"Calculate the mass of sodium hydroxide that the chemist must weigh out in the second step"</em>
To do this, we need to know how much of the base we have to weight to prepare this solution.
First we know that is a sodium hydroxide aqueous solution so, this will dissociate in the ions:
NaOH -------> Na⁺ + OH⁻
As NaOH is a strong base, it will dissociate completely in solution, so, starting with the pH we need to calculate the concentration of OH⁻.
This can be done with the following expression:
14 = pH + pOH
and pOH = -log[OH⁻]
So all we have to do is solve for pOH and then, [OH⁻]. To get the pOH:
pOH = 14 - 13.9 = 0.10
[OH⁻] = 10⁽⁻⁰°¹⁰⁾
[OH⁻] = 0.794 M
Now that we have the concentration, let's calculate the moles that needs to be in the 900 mL:
n = M * V
n = 0.794 * 0.9
n = 0.7146 moles
Finally, to get the mass that need to be weighted, we need to molecular mass of NaOH which is 39.997 g/mol so the mass:
m = 39.997 * 0.7146
<h2>
m = 28.58 g</h2>
La planta perdera su regides
Explanation:por que ya no tendra fuerzas
