Answer:
Total mass of the reactant = 2+2.5 =4.5 mg
Total mass of product = 4.15 mg
therefore, mass of unreacted oxygen = 4.50-4.15 = 0.35 g
342.15 g/mol is the molar mass of Al2(SO4)3 Aluminium sulfate, This is what I found I hope this is right. Hope this helps;)
<u>Answer:</u> The correct answer is Option d.
<u>Explanation:</u>
We are given:
Mass percentage of 
= 20 %
So, mole fraction of = 0.2
Mass percentage of 
= 30 %
So, mole fraction of = 0.3
Mass percentage of 
= 35 %
So, mole fraction of = 0.35
Mass percentage of 
= 15 %
So, mole fraction of = 0.15
We know that:
Molar mass of = 16 g/mol
Molar mass of = 28 g/mol
Molar mass of = 26 g/mol
Molar mass of = 48 g/mol
To calculate the average molecular mass of the mixture, we use the equation:
where,
= mole fractions of i-th species
= molar masses of i-th species
= number of observations
Putting values in above equation:
Hence, the correct answer is Option d.
Answer:
Explanation:
To calculate the cell potential we use the relation:
Eº cell = Eº oxidation + Eº reduction
Now in order to determine which of the species is going to be oxidized, we have to remember that the more the value of the reduction potential is negative, the greater its tendency to be oxidized is. In electrochemistry we use the values of the reductions potential in the tables for simplicity because the only thing we need to do is change the sign of the reduction potential for the oxized species .
So the species that is going to be oxidized is the Aluminium, and therefore:
Eº cell = -( -1.66 V ) + 0.340 V = 5.06 V
Equally valid is to write the equation as:
Eº cell = Eº reduction for the reduced species - Eº reduction for the oxidized species
These two expressions are equivalent, choose the one you fell more comfortable but be careful with the signs.
Answer:
The number of positive charges in nucleus of an atoms are equal to the atomic number and also positive charges are equal to the negative charges which are electrons in neutral atom.
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
Electron:
The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.
Symbol= e⁻
Mass= 9.10938356×10⁻³¹ Kg
It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.
Neutron and proton:
Neutron and proton are present inside the nucleus. Proton has positive charge while neutron is electrically neutral. Proton is discovered by Rutherford while neutron is discovered by James Chadwick in 1932.
Symbol of proton= P⁺
Symbol of neutron= n⁰
Mass of proton=1.672623×10⁻²⁷ Kg
Mass of neutron=1.674929×10⁻²⁷ Kg
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
For example
The carbon have six protons and six neutrons so its atomic mass is 12 amu and atomic number is six.
