Answer:
8 liters of the first salt solution and 12 liters of the second salt solution is needed to get 20L of a solution that is 30% salt
Explanation:
Let x represent the liters of the first salt solution
Let y represent the liters of the second salt solution
x + y= 20......equation 1
x= 20-y
The first solution is 20% salt and the second solution is 45% salt
20/100x + 45/100 y= 30/100 × 20
0.2x + 0.45y= 0.3×20
0.2x + 0.45y= 6............equation 2
Substitute 20-y for x in equation 2
0.2(20-y) + 0.45y= 6
4-0.2y+ 0.45y= 6
4 + 0.25y= 6
0.25y= 6-4
0.25y= 2
y= 2/0.25
y= 8
Substitute y for 8 in equation 1
x + y= 20
x + 8=20
x= 20-8
x= 12
Hence 8 liters of the first salt solution and 12 liters of the second salt solution is needed to get 20L of a solution that is 30% salt.
The last answer choice I believe.
It’s Avogadro number/ constant which is the number of atoms in one mole of a substance.
Answer:
A. Do not change their energy level.
Explanation:
The process in which a solid changes directly to a gas is called sublimation. It occurs when the particles of a solid absorb enough energy to completely overcome the force of attraction between them. Dry ice (solid carbon dioxide, CO2) is an example of a solid that undergoes sublimation.
Hey there!:
1 mole Ag ------------------- 6.02*10²³ atoms
moles Ag ?? --------------- 3.35 *10²² atoms
moles Ag = ( 3.35*10²² ) * 1 / ( 6.02*10²³ ) =
moles Ag = ( 3.35*10²² ) / ( 6.02*10²³ ) =
=> 0.5564 moles of Ag
hope this helps!
