H2(g) +C2H4(g)→C2H6(g)
H-H +H2C =CH2→H3C-Ch3
2C -H bonds and one C-C bond are formed while enthalpy change (dH) of the reaction,
H-H: 432kJ/mol
C=C: 614kJ/mol
C-C: 413 kJ/mol
C-C: 347 kJ/mol
dH is equal to sum of the energies released during the formation of new bonds or negative sign, and sum of energies required to break old bonds or positive sign.
The bond which breaks energy is positive.
432+614 =1046kJ/mol
Formation of bond energy is negative
2(413) + 347 = 1173 kJ/mol
dH reaction is -1173 + 1046 =-127kJ/mol
Answer:
· A chemical reaction is a process generally characterized by a chemical change in which the starting materials (reactants) are different from the products. Chemical reactions tend to involve the motion of electrons, leading to the formation and breaking of chemical bonds. There are several different types of chemical reactions and more than one way of classifying them.
Explanation:
The correct answer is D. In a police interrogation room, questioning the suspect.
Explanation:
Forensic scientists are experts who use science as part of criminal investigations. Indeed, the main role of these experts is to deal with the evidence related to the crime to help authorities understand how the crime occurred and who was involved in this.
Because of this, the forensic scientist's role includes collecting evidence, analyzing samples, participating as witnesses in trials, and in some cases teach other experts about techniques. However, forensic scientists cannot interrogate suspects as they only deal with evidence and this process is in charge of the police.
Answer:
123 g/mol
Explanation:
Let's consider the neutralization reaction.
H₂Z(aq) + 2 NaOH(aq) → Na₂Z(aq) + 2 H₂O(ℓ)
The moles of NaOH that reacted are:
The molar ratio of H₂Z to NaOH is 1:2. The moles of H₂Z that reacted are:
The molar mass of H₂Z is:
