A solution is prepared by dissolving 15.0 g of NH3 in 250 g of water. The density of the resulting solution is 0.974 g/mL. The mole fraction of NH3 in the solution is .A) 16.8B) 0.940C) 0.0597D) 0.922E) 0.0640

Mole fraction of in solution is 0.0597.

Explanation:

Molar mass of = 17.031 g/mol

Molar mass of = 18.015 g/mol

No. of moles = (mass)/(molar mass)

So, 15.0 g of = moles of = 0.8807 moles of

      250 g of = moles of = 13.88 moles of

So, Mole fraction of in the solution = (no.of moles of )/(total no. of moles) = = 0.0597

Hence, mole fraction of in solution is 0.0597.

what's the question?

explanation:

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.