Endothermic<span> Reaction??? </span>
The mass of glycerol to that would need to be combusted to heat 500.0g of water from 20.0°C to 100.0°C is; 9.32 grams.
We must establish the fact that energy is neither created nor destroyed.
Therefore, the amount of heat absorbed by water is equal to the amount of heat released by the combustion of glycerol.
Total heat absorbed by water, H(water) is;
Q(water) = m C (T2 - T1)
Q(water) = 500 × 4.184 × (100-20)
Q(water) = 167.36 kJ
Consequently, the quantity of heat evolved by the combustion of glycerol is;
Q(glycerol) = 167,360 J = n × ΔH°comb
where, n = no. of moles of glycerol.
167.36 kJ= n × 1654 kJ/mole
n = 167.36/1654
n = 0.1012 moles of glycerol.
Therefore, mass of glycerol combusted, m is;
m = n × Molar mass
m = 0.1012 × 92.09
m = 9.32 g.
Read more:
brainly.com/question/20709115
vitamins is the answer to your question
This problem is very easy to answer. You simply have to look at the subscripts of each element of the compound.
1. For caffeine, which has a molecular formula of C₈H₁₀N₄O₂, it contains 8 atoms of Carbon, 10 atoms of Hydrogen, 4 atoms of Nitrogen and 2 atoms of Oxygen.
2. For Iron(III) Sulfate, which has a molecular formula of Fe₂(SO₄)₃, it contains 2 atoms of Iron, 3 atoms of Sulfur, and 12 atoms of Oxygen.
Answer:
- <em>He realized that some elements had not been discovered.</em>
Explanation:
Some scientists that tried to arrange the list of elements known before Mendeleev include Antoine Lavoisier, Johann Döbereiner, Alexandre Béguyer de Chancourtois, John Newlands, and Julius Lothar Meyer.
<em>Dimitri Mendeleev</em> was so succesful that he is recognized as the most important in such work.
Mendeleev by writing the properties of the elements on cards elaborated by him, and "playing" trying to order them, realized that, some properties regularly (periodically) repeated.
The elements were sorted in increasing atomic weight (which is not the actual order in the periodic table), but when an element did not meet the pattern discovered, he moved it to a position were its properties fitted.
The amazing creativity of Mendeleev led him to leave blanks for what he thought were places that should be occupied by elements yet undiscovered. More amazing is that he was able to predict the properties of some of those elements.
When years after some of the elements were discovered, the genius of Mendeleev was proven because the "new" elements had the properties predicted by him.
