Answer:
Element Atomic Number Atomic Mass
Nickel 27 58.6934
Cobalt 28 58.9332
Copper 29 63.546
Zinc 30 65.39
Explanation:
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
Answer:
See figure 1
Explanation:
If we want to find the acid and the Brønsted-Lowry base, we must remember the definition for each of these molecules:
-) Acid: hydrogen donor
-) Base: hydrogen acceptor
In the <u>caffeine structure,</u> we have several atoms of nitrogen. These nitrogen atoms have the ability to <u>accept</u> hydronium ions (
). Therefore the caffeine molecule will be the base since it can accept
If caffeine is the base, the water must be the acid. So, the water in this reaction donated a hydronium ion.
<u>Thus, caffeine is the base and water the acid. (See figure 1)</u>