Molality= moles NaCl/ Kg H2O
250 g (1 Kg/ 1000 grams)= 0.250 Kg
Molality= 0.611 moles/ 0.250 Kg= 2.44 molal
Answer;
Molarity of NaOH is 0.80 M
Explanation;
The balanced equation for the reaction is;
2NaOH(aq) + H2SO4(aq = NaSO4(aq) +2 H2O (l)
Moles = concentration x volume
thus; 0.355M x 0.0282L= 0.01 moles of H2SO4.
Using the mole ratio;
Moles of NaOH = Moles of H2SO4 ×2
= 0.02 Moles
Therefore; moles of NaOH = 0.02 moles
But; Concentration = moles / volume
Thus; Concentration of NaOH = 0.02 / 0.025L
= 0.8M
Benefits of friction.
1. Walking. Friction between the soles of our shoes and the ground enables us to walk. The sole of the shoe is held to the ground through friction. This is what is termed as "grip" of the shoe. The more grip a shoes offers, the better and faster we can walk.
2. Writing. Writing using a pen requires friction. It is impossible to hold a pen in the hand without friction because it would slip out. Also the graphite point of the pencil would not make a mark on the paper without friction.
Drawbacks of friction
1. Drag. An aircraft taking off experiences significant friction between it and the air resulting in drag, so much fuel has to be used to create energy to overcome the wind resistance.
2. Surface hindrance. Friction makes moving something heavy from one part of a room to another very difficult. Sliding a large box across the flour takes a lot of energy due to friction between the box and the floor.
Add gelatin and let it boil, then put it in the freezer for 30 minuets
