How many grams is 2.5 x 10^22 molecules of CH4?

0.67 grams of CH4

Explanation:

To convert from molecules to grams, you need to first convert to moles then convert to grams.

Avogadro's Number (6.022 x 10^23) tells us how many molecules are in a mole.

(2.5 x 10^22)/(6.022 x 10^23) = 0.041514 moles of CH4

Then we convert from moles to grams by multiplying moles of CH4 by the molar mass.

0.041514 moles of CH4 x 16.04 g= 0.67 grams of CH4

true

hope that

first let us lay out the formula for potential

and kinetic energy:

pe = mgh

ke = (mv^2)/2

where: m=mass, v=velocity, g=gravitational

acceleration, h=height

calculating for mass using the known values of

pe:

340j = m (9.81 m/s^2) (50ft) (1m/3.28ft)

m = 2.27 kg

the law of conservation of energy states that

energy is neither created nor destroyed. therefore, the change in kinetic

energy from 50 ft to 35 ft would be equal to the change in potential energy

from 50 ft to 35 ft. however it would be opposite in signs since one is losing

while other is gaining.

ke(35ft) – ke(50ft) = - [ pe(35ft) – pe(50ft]

ke(50ft) = 0 since the brick is initially at rest

ke(35ft) = 340j - 2.27kg (9.81 m/s^2) (35ft)

(1m/3.28 ft)

ke(35ft)

= 102.38 j