When concentration is expressed in molarity, this is equivalent to the number of moles of the solute per liter of solution. We are given with the amount of volume which is 239 mL or 0.239 L. However, there is no known information of the amount of solute. So, I can't give an exact answer. For sample purposes, let's just assume that there is 1 mole of KCl in the solution. The molarity would be:
Molarity = 1 moles/0.239 L = 4.184 M
Answer:
1.56 g of water was involved in the reaction
Explanation:
From the stoichiometric equation
2Na + 2H2O = 2NaOH + H2
NB : Mm Na= 23, Mm H2O = ( 2+16)= 18
2(23) of Na requires 2(18) of water
Hence 1.99g of Na will require 1.99×2×18/2(23) of water = 1.56 g of water
Answer: The best way to promote the process are:
--> Add a bit of solid as a seed crystal.
--> Scratch the bottom of the flask gently with a stirring rod.
Explanation:
A crystal growth is seen is SUPERSATURATED solutions which contains more solute than it can normally dissolve at that given temperature. It is usually very UNSTABLE and capable of releasing the excess solute if disturbed, either by shaking or seeding with a tiny crystals.
Crystallization can be used for the separation of two salts with different solubilities as well as for purification of a soluble salt that contains insoluble solid impurities. Recrystallization improves the validity of the process. Crystallization can be initiated by:
--> Scratching the bottom of the flask gently with a stirring rod: scratching initiates crystallization by providing energy from the high-frequency vibrations.
--> Adding a bit of solid as a seed crystal: Seed crystals create a nucleation site where crystals can begin growth.
Answer:
C4H8
Explanation:
First find the molar mass of CH2;
2(1.01) + 1(12.01) = 14.03g
Now divide the molar mass of the compound by the molar mass of CH2;
56g/14.03g = 3.9914 Round to nearest whole number = 4
Multiply CH2 by 4 to get the molecular formula;
CH2* 4 = C4H8
