Answer:
2 electrons from magnesium (Mg) is transferred to oxygen (O2) to form Mg2+ and O2-
which combines by strong electrostatic force to form MgO
the equation is
2Mg + O2 -> 2MgO
Answer:
a) [NH2]-,
b) [O]2-
c) [Cl]-
Explanation:
The conjugate base is the base member (X⁻) of a weak acid (HX). In other words, the conjugate base is the remaining substance due to the proton loss in the acid HX.
a) For NH₃, (HX; X: NH₂⁻), conjugate base is NH₂⁻. In the format, <em>[NH2]-</em>.
b) For OH⁻, (HX; X: O²⁻), conjugate base is O²⁻. In the format,<em> [O]2-</em>.
c) For HCl, (HX; X: Cl⁻), conjugate base is Cl⁻. In the format, <em>[Cl]-</em>.
<u>Answer:</u> The empirical and molecular formula of the compound is
and
respectively
<u>Explanation:</u>
We are given:
Mass of C = 3.758 g
Mass of H = 0.316 g
Mass of O = 1.251 g
To formulate the empirical formula, we need to follow some steps:
- <u>Step 1:</u> Converting the given masses into moles.
Moles of Carbon =
Moles of Hydrogen = 
Moles of Oxygen = 
- <u>Step 2:</u> Calculating the mole ratio of the given elements.
For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.078 moles.
For Carbon = 
For Hydrogen = 
For Oxygen = 
- <u>Step 3:</u> Taking the mole ratio as their subscripts.
The ratio of C : H : O = 4 : 4 : 1
The empirical formula for the given compound is 
For determining the molecular formula, we need to determine the valency which is multiplied by each element to get the molecular formula.
The equation used to calculate the valency is:

We are given:
Mass of molecular formula = 130 g/mol
Mass of empirical formula = 68 g/mol
Putting values in above equation, we get:

Multiplying this valency by the subscript of every element of empirical formula, we get:

Hence, the empirical and molecular formula of the compound is
and
respectively
Through manipulation of equations, we are able to obtain the equation:
![-pOH= log [ OH^{-}]](https://tex.z-dn.net/?f=-pOH%3D%20log%20%5B%20OH%5E%7B-%7D%5D%20)
Then we can transform the equation into:
![[ OH^{-}]= 10^{-pOH}](https://tex.z-dn.net/?f=%5B%20OH%5E%7B-%7D%5D%3D%2010%5E%7B-pOH%7D%20%20)
Then we are able to plug in the pOH and directly get [OH-]:
![[ OH^{-}] = 10^{-6.48}](https://tex.z-dn.net/?f=%5B%20OH%5E%7B-%7D%5D%20%3D%2010%5E%7B-6.48%7D%20)