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QUESTION;
Understanding the enthalpy definition=
Measurements show that the enthalpy of a mixture of gaseous reactants increases by 125.kJ during a certain chemical reaction, which is carried out at a constant pressure. Furthermore, by carefully monitoring the volume change it is determined that -71.kJ of work is done on the mixture during the reaction. Calculate the change in enthalpy of the gas mixture during the reaction and determine if the reaction is endothermic or exothermic.
ANSWER: The change in enthalpy of the gas mixture during the reaction is 54.kJ
The reaction is endothermic.
EXPLANATION: Enthalpy is the heat change in a system.
To calculate enthalpy we use the formula below;
H = E + PV
H is the enthalpy
E is the energy used in the reaction
PV is the product of pressure and volume which is refered to as the work done in the system
Using the equation above
H = 125 + (-71) = 54.kJ
An endothermic reaction is a type of reaction where heat is gained by the system from it's environment, and the enthalpy of such system is positive. While an Exothermic reaction is a type of reaction where heat is lost by the system to it's environment, and the enthalpy of such system is negative.
Because our enthalpy value is positive, this is an endothermic reaction.
The compounds that have covalent bonding as their dominant bonding scheme are diamond and silica.
A covalent bond is formed between two nonmetals. Usually, when two nonmetals combine, electrons are shared between the two atoms involved in the bond.
Now, the solids diamond and silica are predominantly covalent solids. The atoms that combine in diamond are carbon atoms(nonmetals) while the atoms that combine in silica are silicon and oxygen (nonmetals also)
Hence, diamond and silica both have covalent bonding as their dominant bonding scheme.
Learn more: brainly.com/question/11527546
Hello there.
Question: <span>Which of the following best describes the freezing of water?
negative change in enthalpy, low temperature and positive entropy
A. negative change in enthalpy, low temperature and negative entropy
B. positive change in enthalpy, low temperature and positive entropy
C. positive change in enthalpy,low temperature and negative entropy
D. negative change in enthalpy, high temperature and negative entropy.
Answer: It would be option A. </span>negative change in enthalpy, low temperature and negative entropy
Hope This Helps You!
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Pb(NO3)2 + 2KCl ------) PbCl2 + 2KNO3
Pb+2 + 2Cl- ---------) PbCl2
Answer: 22.4L
Gas at STP means gas at standard temperature and pressure of one mole of an ideal gas
Ideal gas Law PV=nRT
Standard pressure is 1atm or 22.4L
Standard temperature is 273.15K
Any questions feel free to ask. Thanks