I think you might find your answer here https://answers.yahoo.com/question/index?qid=20121101101721AAeZyHE
Answer:
1. relative time
2.absolute time
Explanation:
Time that is measured in definite periods such as minutes, days, and years is called
a. Relative time.
b. absolute time.
Answer:
The standard enthalpy of formation of this isomer of octane is -220.1 kJ/mol
Explanation:
Step 1: Data given
The combustion reaction of octane produces 5104.1 kJ per mol octane
Step 2: The balanced equation
C8H18(g) + 12.5 O2 ⟶ 8CO2 (g) + 9 H2O (g) ∆H°rxn = -5104.1 kJ/mol
Step 3:
∆H°rxn = ∆H°f of products minus the ∆H° of reactants
∆H°rxn = ∆H°f products - [∆H°f reactants]
-5104.1 kJ/mol = (8*∆H°fCO2 + 9*∆H°fH20) - (∆H°fC8H18 + 12.5∆H°fO2)
∆H°f C8H18 = ∆H°f 8CO2 + ∆H°f 9H2O+ 5104.1 kJ/mol
∆H°f C8H18 = 8 * (-393.5 kJ)/mol + 9 * (-241.8 kJ/mol)] + 5104.1 kJ
/mol
∆H°f C8H18 = -220.1 kJ/mol
The standard enthalpy of formation of this isomer of octane is -220.1 kJ/mol
Answer:
Option D. ZnCl₂ and H₂
Explanation:
From the question given above, the following equation was obtained:
2HCl + Zn —> ZnCl₂ + H₂
Products =?
In a chemical equation, reactants are located on the left side while products are located on the right side i.e
Reactants —> Products
Now, considering the equation from the question i.e
2HCl + Zn —> ZnCl₂ + H₂
The products are ZnCl₂ and H₂ because from our discussion above, we said that products are only located on the right side of chemical equation.
Thus, option D gives the correct answer to the question.
There can be a lot of meanings for isomers. In this case, we are showing the structural isomers of C₇H₁₆. Based on the chemical formula, CₓH₂ₓ₊₂ it is an alkane. They only differ in the positions of methane branches in the parent carbon chain. Basing on the attached picture, the parent carbon chain is pentane for both isomers. But the methyl branches are on the 2nd & 4th, and 2nd & 3rd carbon for 2,4 - dimethylpentane and 2,3 - dimethylpentane, respectively.
