Metilamino laisvosios bazės tirpalo paruošimas

[B APPLE]

Teacher, may I ask if after adding sodium hydroxide to the water and stirring until dissolved, it will no longer be transparent！

 

[mycelium]

It literally says that you WAIT FOR THE EXOTHERMIC REACTION TO BE DONE which is clear liquid and cooled down

 

[Arakava]

I used 57g menh2 hcl + 34g naoh in 46g water. My collecting flask contained 82g water. At the end I collected 126g methylamine solution. It means 44g added to final solution. Is it possible? 44g menh2 of 57g menh2 hcl?
Or water also was evaporating with menh2? Because boiling flask temperature slowly reached 85°c.

 

[G.Patton]

You can count and check it like this:
Molar amount of 57g MeNH*HCl = 57/67.518 = 0.844 moles.
How much grams of MeNH2 can it gives? 0.844 mol * 31.1 g/mol(molar mass of MeNH2)= 26.3 g

I assume that there is water as well.

 

[Arakava]

Sir! I tested something. I poured 100ml tap water + 5g naoh in a flask and pour 120ml tap water in a 100ml graduated cylinder. I heated the flask .at around 96°C bubbles occurred. (IN MY AREA WATER BOILS AT 96°C.) So water won't bublle out bellow boiling point. At lesser water in graduated cylinder bubbles occur sooner. Because of lower height of the water in graduated cylinder, bubbles can come out easier. So how would water come out in present of menh2 at lower temperature? (I had 100ml water in graduated cylinder, and 57g menh2 in the flask)