The chemical formula for the compound can be written as,
CxHyOz
where x is the number of C atoms, y is the number of H atoms, and z is the number of O atoms. The combustion reaction for this compound is,
CxHyOz + O2 --> CO2 + H2O
number of moles of C:
(0.7191 g)(1 mol CO2/44 g of CO2) = 0.0163 mol CO2
This signifies that 0.0163 mole of C and the mass of carbon in the compound,
(0.0163 mols C)(12 g C/ 1 mol C) = 0.196 g C
number of moles H:
(0.1472 g H2O)(1 mol H2O/18 g H2O) = 0.00818 mol H2O
This signifies that there are 0.01635 atoms of H in the compound.
mass of H in the compound = (0.01635 mols H)(1 g of H) = 0.01635 g H
Mass of oxygen in the compound,
0.3870 - (0.196 g C + 0.01635 g H) = 0.1746 g
Moles O in the compound = (0.1746 g O)(1 mol O/16 g O) = 0.0109 mols O
The formula of the compound is,
C0.0163H0.01635O0.0109
Dividing the numbers by the least number,
C3/2H3/2O
The empirical formula of the compound is therefore,
<em> C₃H₃O₂</em>
The total energy can be found by adding the different energies:
628 + 15,600 + 712
= 16.94 kJ
Answer:
Chemicals A and B form an endothermic reaction, and chemicals C and D form an exothermic reaction.
Explanation:
The reaction that produced chemical C is an endothermic reaction whereas, the reaction between C and D is an exothermic one.
An exothermic change is one in which heat is liberated to the surroundings. So the surrounding becomes hotter at the end of the reaction.
An endothermic reaction is a change in which heat is absorbed from the surrounding and hence the surrounding colder at the end of the change.
- We can see that the first reaction is endothermic.
- The second reaction is exothermic.
The answer is the choice A
Answer:
Kinetic energy is transferred from the leg to the soccer ball.
Explanation:
