<u>Answer:</u> The elevation in boiling point is 1.024°C.
<u>Explanation:</u>
To calculate the elevation in boiling point, we use the equation:

where,
i = Van't Hoff factor = 2 (for NaCl)
= change in boiling point = ?
= boiling point constant = 
m = molality = 1.0 m
Putting values in above equation, we get:

Hence, the elevation in boiling point is 1.024°C.
Since momentum is a vector quantity, take any direction as positive and other as negative. Answer won't change.
Answer:
Explanation:
We shall apply concept of impulse to solve the problem .
Impulse = force x time
impulse = change in momentum
force x time = change in momentum
initial speed u = 24 km/h = 6.67 m /s
final speed v = 65 km/h = 18.05 m /s
change in momentum = m v - mu
= m ( v-u )
= 1350 ( 18.05 - 6.67 )
= 15363 kg m/s
F x 18 = 15363
F = 853.5 N .
Given :
The ball of a ballpoint pen is 0.5 mm in diameter and has an ASTM grain size of 12.
To Find :
How many grains are there in the ball?
Solution :
Volume of ball of the ballpoint is :

Now, grain size of 12 has about 520000 grains/mm³.
Therefore, number of grains are :
