The number of protons is equal to the atomic number of every element in the periodic table.
Example: The atomic number of Niobium (Nb) is 41. Therefore, the number of protons is also 41.
The theoretical yield of urea : = 227.4 kg
<h3>Further explanation</h3>
Given
Reaction
2NH3(aq)+CO2(aq)→CH4N2O(aq)+H2O(l)
128.9 kg of ammonia
211.4 kg of carbon dioxide
166.3 kg of urea.
Required
The theoretical yield of urea
Solution
mol Ammonia (MW=17 g/mol)
=128.9 : 17
= 7.58 kmol
mol CO₂(MW=44 g/mol) :
= 211.4 : 44
= 4.805 kmol
Mol : coefficient of reactant , NH₃ : CO₂ :
= 7.58/2 : 4.805/1
=3.79 : 4.805
Ammonia as limiting reactant(smaller ratio)
Mol urea based on mol Ammonia :
=1/2 x 7.58
=3.79 kmol
Mass urea :
=3.79 kmol x 60 g/mol
= 227.4 kg
Answer:
The total heat required is 3.4 kJ
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
There is a direct proportional relationship between heat and temperature. So, the amount of heat a body receives or transmits is determined by:
Q = c * m * ΔT
where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.
In this case you know;
- c= 4

- m= 10 g
- ΔT= Tfinal - Tinitial= 10 C - 0 C= 10 C
Replacing:

Solving:
<em>Q1= 400 J</em>
On the other hand, you must determine the heat required to convert 0 ∘ C of ice to 0 ∘ C of liquid water by:
Q2=m*heat of fusion
Q2=10 g* 300 
<em>Q2= 3,000 J</em>
The total heat required is:
Q= Q1 + Q2= 400 J + 3,000 J
Q= 3,400 J= 3.4 kJ (1 kJ= 1,000 J)
<u><em>The total heat required is 3.4 kJ</em></u>
Water, lower, and I'm not too sure for the third one... sorry.