By adding the enthalpies of the intermediate reactions together to get the enthalpy of the desired reaction
Ok to answer this question we firsst need to fin the number of mol of Urea (CH4N2O). to do this we simply :
1 mol of urea =15/60.055 = 0.25mol
therefore 200g of water contain 0.25mol
the next step is to determine the malality of our solution in 200g of water, to do this we say:
200 g = 1Kg/1000g = 0.2kg
therefor 0.25mol/0.2Kg = 1.25mol/kg
and from the equation:
we know that i = 1
we are given Kf
b is the molality that we just calculated
therefore;
the solutions freezing point is -2.325°C
There are 4 significant figures! Start counting after the first non-zero digit :)
Hope this helps.
Answer:
RbOH
Explanation:
For this question, we have to remember what is the definition of a base. A base is a compound that has the <u>ability to produce hydroxyl ions</u>
, so:

With this in mind we can write the <u>reaction for each substance:</u>




The only compound that fits with the definition is
, so this is our <u>base</u>.
I hope it helps!
1: the symbol of the metal should be written first.
2: the valency of the elements or radicals should be interchanged.