Compounds that are formed when two or more atoms combine to form molecules are called Molecular Compounds.
Recall that most atoms are stable when their outermost ring has eight electrons. (Some atoms, such as lithium and beryllium, are stable when their outermost ring has two electrons.)
Answer:
1.57×10²³ molecules
Explanation:
Given data:
Number of molecules of ethanol = ?
Volume of ethanol = 15.0 mL
Density of ethanol = 0.789 g/mL
Solution:
Mass of ethanol :
Density = mass/ volume
0.789 g/mL = mass/ 15.0 mL
Mass = 0.789 g/mL× 15.0 mL
Mass = 11.84 g
Number of moles of ethanol:
Number of moles = mass/molar mass
Number of moles = 11.84 g / 46.07 g/mol
Number of moles = 0.26 mol
1 mole contain 6.022×10²³ molecules
0.26 mol × 6.022×10²³ molecules / 1mol
1.57×10²³ molecules
Answer:
Molar mass = 12.51 g/mol
Explanation:
V = 3L
P = 1.25 atm
T = 20 C = 20 + 273 = 293 K (Upon conversion to kelvin temperature)
n =?
m = 1.95g
Molar mass = ?
The variables are related by the follwing equation;
pV = nRT
where r = gas constant = 0.0821 L atm K−1
Solving for n, we have;
n = pV / RT
n = (1.25 * 3 ) / (0.0821 * 293)
n = 3.75 / 24.0553 = 0.1559 mol
The relationship between number of moles, n and molar mass is given as;
n = mass / molar mass
Molar mass = Mass / n = 1.95 / 0.1559
Molar mass = 12.51 g/mol
