To determine the number of moles of a gas, we need to have an expression that relates the pressure, temperature and volume of the system. For simplification, we assume that this gas is ideal so we use the equation PV=nRT. We calculate as follows:
PV=nRT
n = PV / RT
n = 235000(1.48x10^-4) / (8.314)(40+273.15)
n = 0.01336 mol
They should report the density as 1.11 g/L
.
Density = mass/volume = 2.260g/2.04 mL
My calculator says the density <em>1.107 843 137 g/mL</em>
However, the answer can have <em>no more</em> significant figures than are in the number with the <em>fewest </em>significant figures.
The volume measurement has only three significant figures, so we must round off the density to three significant figures.
We drop all the digits after the zero.
The digit to be dropped is 7, so we <em>round up </em>the last significant figure of the answer.
1.10<u>7 843 137</u> → 1.11
Answer: 8 dots would be needed to represent the outer electrons for an atom of neon in an electron dot diagram.
Explanation:
Electron-dot diagram is also known as Lewis-dot structure. It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule. The valence electrons are represented by 'dot'.
As atomic number of neon is 10 and we know that neon has 10 electrons with electronic configuration of 2,8 and thus has '8' valence electrons.
Therefore, the total number of valence electrons is 8 and 8 dots would be needed to represent the outer electrons for an atom of neon in an electron dot diagram.
A. Intermediate is the answer
