Answer: The sum of the coefficients needed to balance the combustion reaction of methane is 6.
Explanation:
Combustion is a chemical reaction in which hydrocarbons are burnt in the presence of oxygen to give carbon dioxide and water.
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.
The chemical equation for combustion of methane will be :
The coefficient foer methane is 1 , 2 for oxygen , 1 for carbon dioxide and 2 for water. The sum is 6.
Answer:
Molecular formula = C₂H₄Cl₂
Explanation:
Molecular formula:
Molecular formula consist of symbols of elements present in compound with numbers of atoms of each element in subscript.
Empirical formula:
It is the simplest formula gives the ratio of atoms of different elements in small whole number .
Given data:
Percentage of hydrogen = 4.07%
Percentage of Cl = 71.65%
Percentage of carbon = 24.27%
Molar mass = 99 g/mol
Molecular formula = ?
Solution:
Number of gram atoms of H = 4.07 / 1.01 = 4.0
Number of gram atoms of Cl = 71.65 / 35.5 = 2.0
Number of gram atoms of C = 24.27 / 12 = 2.0
Atomic ratio:
H : C : Cl
4/2 : 2/2 : 2/2
2 : 1 : 1
C : H : Cl = 1 : 2 : 1
Empirical formula is CH₂Cl.
Molecular formula:
Molecular formula = n (empirical formula)
n = molar mass of compound / empirical formula mass
Empirical formula mass = 12+1×2+ 35.5 = 49.5
n = 99/49.5
n = 2
Molecular formula = n (empirical formula)
Molecular formula = 2 ( CH₂Cl)
Molecular formula = C₂H₄Cl₂
Electrons = protons
protons = atomic number
protons + neutrons = atomic mass
Therefore: a) protons + 7 = 15
protons= 15 -7
protons= 8
B) Remember proton = atomic number
so atomic number = 8
C)Now we know the atomic number so we can easily check on the periodic table what element has an atomic number of 8, which is Oxygen
<h3><u>Answer;</u></h3>
= 9.45 × 10^23 molecules
<h3><u>Explanation; </u></h3>
The molar mass of Na2SO4 = 142.04 g/mol
Number of moles = mass/molar mass
= 223/142.04
= 1.57 moles
But;
1 mole = 6.02 × 10^23 molecules
Therefore;
1.57 moles = ?
= 1.57 × 6.02 × 10^23 molecules
<u>= 9.45 × 10^23 molecules </u>
