1. 92 g
2. 5.4 g
3. 0.217 moles
Further explanation
The mole is the number of particles(molecules, atoms, ions) contained in a substance
1 mol = 6.02.10²³ particles
Can be formulated
N=n x No
N = number of particles
n = mol
No = Avogadro's = 6.02.10²³
Moles can also be determined from the amount of substance mass and its molar mass
[tex]\tt n=\dfrac{m}{MW}[/tex]
1. the mass of 4 moles of Na(MW= 23 g/mol)
[tex]\tt mass=mol\times MW\\\\mass=4\times 23\\\\mass=92~g[/tex]
2. the mass of 0.3 moles of water(MW=18 g/mol)
[tex]\tt mass=mol\times MW\\\\mass=0.3\times 18\\\\mass=5.4~g[/tex]
3. the number of moles found in 10g of ethanol C2H5OH(MW=46 g/mol) :
[tex]\tt mol=\dfrac{10}{46}\\\\mol=0.217[/tex]
