Intermolecular forces are the forces of attraction or repulsion which act between neighboring particles (atoms, molecules, or ions ). These forces are weak compared to the intramolecular forces, such as the covalent or ionic bonds between atoms in a molecule.
We are going to use Avogadro's constant to calculate how many molecules of
carbons dioxide exist in lungs:
when 1 mole of CO2 has 6.02 x 10^23 molecules, so how many molecules in
CO2 when the number of moles is 5 x 10^-2
number of molecules = moles of CO2 * Avogadro's number
= 5 x 10^-2 * 6.02 x 10^23
= 3 x 10^22 molecules
∴ There are 3 x 10^22 molecules in CO2 exist in lungs
Answer:
2.25g of NaF are needed to prepare the buffer of pH = 3.2
Explanation:
The mixture of a weak acid (HF) with its conjugate base (NaF), produce a buffer. To find the pH of a buffer we must use H-H equation:
pH = pKa + log [A-] / [HA]
<em>Where pH is the pH of the buffer that you want = 3.2, pKa is the pKa of HF = 3.17, and [] could be taken as the moles of A-, the conjugate base (NaF) and the weak acid, HA, (HF). </em>
The moles of HF are:
500mL = 0.500L * (0.100mol/L) = 0.0500 moles HF
Replacing:
3.2 = 3.17 + log [A-] / [0.0500moles]
0.03 = log [A-] / [0.0500moles]
1.017152 = [A-] / [0.0500moles]
[A-] = 0.0500mol * 1.017152
[A-] = 0.0536 moles NaF
The mass could be obtained using the molar mass of NaF (41.99g/mol):
0.0536 moles NaF * (41.99g/mol) =
<h3>2.25g of NaF are needed to prepare the buffer of pH = 3.2</h3>
The empirical formula is the simplest form of the formula expressed in the lowest ratio. In this case, we just have to divide each subscript by the greatest common factor. Hence.
a. CN
b. P2O5
c.N2O5
d.NaCl
e. C9H20
f. BH3
g.K2Cr2O7
h.AlB3
i.CH
j.SiCl4
