15.5% by mass is
equivalent 15.5 g urea in 100 g solution or 155 g urea in 1 kg solution. <span>
<span>we know that molality = moles solute / kg solvent
<span>moles solute = 155 g / 60 g/mol = 2.58 moles urea
</span></span></span>
Since there are 155 g
urea in 1000g solution, hence the solvent is 845 g or 0.845 kg
So:<span>
<span>molality = 2.58 / 0.845 = 3.06 m</span></span>
Explanation:
Bond forming:
Given species:
Na - Sodium Cl - Chlorine
Na has a valence electron
Cl has 7 valence electron
To form a bond of this nature, there must be a transfer of electrons.
Here, the bond is between a metal and non-metal
The metal is sodium and the non-metal is chlorine;
Na → Na⁺ + e⁻ loss of 1 electron
2,8,1 2,8
isoelectronic with Neon
Cl + e → Cl⁻ gain of one electron
isoelectronic with Argon
Na⁺ + Cl⁻ → Na⁺.Cl⁻
This bond type is an ionic bond
The class can break or if you put it in cold water it can cool down down fast.
