75.0 mL of 15.0 M HNO3 was diluted to exactly 500 mL by adding water. What is the final molarity of the diluted HNO3 solution?

The final molarity is 2,25M.

Explanation:

A dilution consists of the decrease of concentration of a substance in a solution (the higher the volume of the solvent, the lower the concentration).

We use the formula for dilutions:

C1 x V1 = C2 x V2

15,0 M x 75 ml = C2 x 500 ml

C2= (15,0M x 75 ml)/500ml

C2=2,25 M

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.

particle   p is an electron and particle q is a neutron