How many molecules are present in 3.09 mol of silicon dioxide, SiO2

There are 1.86 x 10²⁴ molecules of Silicon dioxide, SiO₂

The mole is the number of particles(molecules, atoms, ions) contained in a substance

Moles can also be determined from the amount of substance mass and its molar mass

1 mol = 6.02.10²³  particles

Can be formulated

N = number of particles

n = mol

No = Avogadro's = 6.02.10²³

3.09 mol of Silicon dioxide, SiO₂

n=mol=3.09

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g

gas

explanation:

smoke is the matter of a gas