Question

what is the mass of 5×6.022×10^23 CH4 molecules​

Answer 1

Answer:

80.2

Explanation:

amount of moles=mass/molecular weight

for this problem, you need the avogadro number. it's a constant. the avogadro number tells you how many particles there are in a mole. that's why a mole is called the chemists dozen. 1 mole = 6.022 x 10^23, which is the avogadro number.

in this problem, you are given 5 times of the amount of the avogadro number, so you have 5x as much molecules.

you basically need this formula to solve.

n(amount of moles)=m(mass)/mw(molecular weight)

since 1 mole is 6.022 x 10^23, you are given 5 moles of CH4. The molecular weight of CH4 is, c + 4h. the molecular weight of c is 12, and h is one. so the molecular weight of CH4(methane) will be approximately 16. but this is rounded up, so if you want a more accurate result, use 16.04, the actual value.

moles(n)=5, mw=16.04

mass= mw*n

mass=5*16.04

=80.2

hope this helped (: