Answer:
C3H6O
Explanation:
The percentage composition of the elements in the compound are given as follows:
62.1 % carbon = 62.1g of C
10.5 % hydrogen = 10.5g of H
27.6 % oxygen = 27.6g of O
Next, we convert each mass to mole by dividing by their molar/atomic mass
C = 62.1/12 = 5.175mol
H = 10.5/1 = 10.5mol
O = 27.6/16 = 1.725mol
Next, we divide each mole value by the smallest mole value (1.725)
C = 5.175mol ÷ 1.725 = 3
H = 10.5mol ÷ 1.725 = 6.086
O = 1.725mol ÷ 1.725 = 1
The empirical ratio approximately of C:H:O is 3:6:1, hence, the empirical formula is C3H6O
Answer:
1. Draw only the valence electrons.
2. Give every element main group element (except hydrogen) an octet of electrons.
3. Give each hydrogen two electrons.
Explanation:
Lewis structures are used to describe the arrangement or configurations of the valence electrons of molecules and polyatomic ions involved in electronic bonding. A Lewis structure consists of the symbols of the elements in the molecule surrounded by dots with each dot representing each of the elements valence electrons. Also, the electrons shared between two elements are shown by dots between the two elements and these electrons are known as shared electron pairs. The valence electrons on atom that is not involved in bonding is known as lone pairs.
The three general rules for drawing Lewis structures are:
1. Draw only the valence electrons. Only the valence electrons of the atoms of elements are shown since they are the only electrons involved in chemical bonding.
2. Give every element main group element (except hydrogen) an octet of electrons. The complete eight valence electrons of the noble gases is associated with their stability. Thus, the main group elements show a tendency to form enough bonds to obtain eight valence electronsmin order to achieve stability. This is known as the octet rule. However, since the maximum number of valence electrons for elements in the first period of the period table is two, the noble gas helium has completely-filled valence shell containing two electrons known as a duplet. Hydrogen belongs to the first period and is therefore an exception tomthe octet rule.
3. Give each hydrogen two electrons. Hydrogen attains a duplet structure in accordance with the structure of helium
I think it takes about 2 weeks to go from H to B on the diagram since H is the new moon and B is the full moon so going from H to B represents half of the lunar cycle and one lunar cycle takes about 28 days (which is about 4 weeks).
The base dissociation constant or Kb is a value used to measure
the strength of a specific base in solution. To determine the percent ionization
of the substance we make use of the Kb given. Methylamine or CH3NH2 when
in solution would form ions:
CH3NH2 + H2O < = > CH3NH3+ + OH-
Kb is expressed as follows:
<span>
Kb = [OH-] [CH3NH3+] / [CH3NH2]
Where the terms represents the concentrations of the acid and the ions.
By the ICE table, we can calculate the equilibrium concentrations,
CH3NH2 CH3NH3+
OH-
I 1.60 0
0
C -x +x
+x
--------------------------------------------------
E 1.60-x x
x
Kb = [OH-] [CH3NH3+] / [CH3NH2] = </span> 3.4×10−4
<span> 3.4×10−4</span> = x^2 / 1.60-x
Solving for x,
x = [OH-] = 0.023 M
pH = 14 + log 0.023 = 12.36
Therefore, the first option is the closest one.