The molecular formula for compound is 
mass of compound is 0.670 g.
To calculate number of atoms first calculate number of moles in the compound as follows:
Molar mass of is 283.886 g/mol, thus,
Thus, number of mole of is 0.00236 mol.
From the molecular formula 1 mole of has 2 mol of P (phosphorus) and 5 mol of O (oxygen).
Thus, number of moles of P and O in 0.00236 mol of will be:
Similarly,
Now, in 1 mol of an element there are 
atoms.
Number of atoms of P will be:
Similarly, number of atoms of O will be:
Total number of atoms will be sum of number of atoms of P and O:
Therefore, total number of atoms in will be 
.
It's the number of Protons of that atom..
Answer:
Equilibrium constant Kc = Qc = quotient of reactant(s) and product(s)
Kc = [C]x[D]y..../[A]m[B]n..... = 0.328dm3/mol, where [C]x[D]y is the product and [A]m[B]n is the reactant(Both in gaseous states)
Explanation:
When a mixture of reactants and products of a reaction reaches equilibrium at a given temperature, its reaction quotient always has the same value. This value is called the equilibrium constant (K) of the reaction at that temperature. As for the reaction quotient, when evaluated in terms of concentrations, it is noted as Kc.
That a reaction quotient always assumes the same value at equilibrium can be expressed as:
Qc (at equilibrium) = Kc =[C]x[D]y…/[A]m[B]n…
This equation is a mathematical statement of the law of mass action: When a reaction has attained equilibrium at a given temperature, the reaction quotient for the reaction always has the same value.
Answer:
4.1x10⁻⁵
Explanation:
The dissociation of an acid is a reversible reaction, and, because of that, it has an equilibrium constant, Ka. For a generic acid (HA), the dissociation happens by:
HA ⇄ H⁺ + A⁻
So, if x moles of the acid dissociates, x moles of H⁺ and x moles of A⁻ is formed. the percent of dissociation of the acid is:
% = (dissociated/total)*100%
4.4% = (x/[HA])*100%
But x = [A⁻], so:
[A⁻]/[HA] = 0.044
The pH of the acid can be calcualted by the Handersson-Halsebach equation:
pH = pKa + log[A⁻]/[HA]
3.03 = pKa + log 0.044
pKa = 3.03 - log 0.044
pKa = 4.39
pKa = -logKa
logKa = -pKa
Ka = 
Ka = 
Ka = 4.1x10⁻⁵
Answer:
e. all of these
Explanation:
Let us check all the given options one by one:
a.The nucleus is positively charged.
Yes it is correct since nucleus contain protons and neutrons and protons are positively charged.
b.The nucleus contains both charged and uncharged particles.
Yes because protons are positively charged and neutrons are neutral in nature.
c.The electrons contribute very little to the total mass of the atom.
Yes we know all the mass of the atom is considered in center and mass of electron is negligible as compared to protons and neutrons.
d.The electrons are located in the atomic space outside the nucleus.
Yes, its a known fact.
e. All of these.
Since , all given options are correct .
Therefore , option e. is right .
