The volume at STP : 9.856 L
<h3>Further explanation</h3>
Given
Mass of ethane : 13.21 g
Required
The volume at STP
Solution
Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters / mol.
mol ethane(C2H6) :
= mass : molar mass
= 13.21 g : 30 g/mol
= 0.44
Volume at STP :
= 0.44 x 22.4 L
= 9.856 L
Molar mass of 13c = 13 grams
number of moles = mass / molar mass
therefore,
number of moles = 7 / 13
To know the number of atoms in 7/13 moles, we simply multiply the number of moles by Avogadro's number as follows:
number of atoms = (7/13) x 6.022 x 10^23 = 3.2426 x 10^23 atoms
The answer is 40.
We can solve this by finding out the number of protons, and neutrons. Atomic number of an element means the number of protons in that element. So, the atom has 30 protons if the atomic number is 30.
On the other hand, mass number is the total number of protons and neutrons, but not electrons, because they're too light comparing to the other 2. Therefore, we can simply solve the number of neutrons in the atom by subtracting the number of protons from the mass number. 70 - 30 = 40.
Therfore, the number of neutrons is 40.
I think it’s B 5.54 x 10^2g
The answer is "Incidents"