Calculate the amount of moles in 1.17 x 1016 molecules of H2S.

Explanation:

To convert from molecules to moles, Avogadro's Number must be used.

This number tells us how many particles (atoms, ions, molecules, etc.) are in 1 mole of a substance. For this problem, it is moles of hydrogen sulfide.

We can use the number as a fraction.

Multiply by the given number of molecules.

Flip the fraction so the molecules of hydrogen sulfide will cancel out.

The original measurement of molecules had 3 significant figures so we must round our answer to that.

For the number we calculated, that is the hundredth place. The 2 in the thousandth place tells us to leave the 4 in the hundredth place.

There are about 1.94*10⁻⁸ molecules of hydrogen sulfide.

what is the general relationship between a galaxy's distance from earth and its speed?

the answer is:

the farther away a galaxy is from us, the faster it is moving away from us.

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"