Asolution is prepared by dissolving 12.7 g ammonium sulfate in enough water to make 124.0 ml of stock solution. a 13.70-ml sample of this stock solution is added to 56.50 ml of water. calculate the concentration of ammonium ions and sulfate ions in the final solution.

a) Ammonia — 0.3025M

b) sulphate — 0.1512M

Explanation:

Molarity = mol solute / L solution

Mass of the solution = 12.7 x (1/132.14) = 0.0961 mol in 124mL

Molarity = 0.0961/0.124 L solution = 0.775M

So 13.70 ml of this solution is added to 56.50 mL we have 70.2 mL total solution

Now using dilution equation

M1V1 = M2V2

To find the molarity of the new 70.2mL solution

(0.775M x 13.7 ) = M2 x 70.2

M2 = (0.775M x 13.7 ) / 70.2 = 0.1512M

Therefore there’s 0.1512 moles ammonia sulphate per liter of the solution

Therefore the concentration of Ion is

1. 2 x 0.1512 = 0.3025M of ammonia

2. 1 x 0.1512 = 0.1512M of sulphate

it doesn't. it was imagined up in the middle ages.

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s