Answer:0.56L
Explanation:Molar mass of O2=32
N=0.8/32
N=0.025
V=0.025 x 22.4=0.56L
For each of the environments below: (1) identify your system and surroundings and (2) predict whether it would be endothermic or exothermic.a.Wood burningSystem:Surroundings:Enthalpy Change:b.Water freezingSystem:Surroundings:Enthalpy Change:c.Sweat evaporatingSystem:Surroundings:Enthalpy Change:d.Chemical hand-warmerSystem:Surroundings:Enthalpy Change:
Answer:
A) Wood burning
system : Wood.
surroundings : atmosphere
Enthalpy : Exothermic
B) Water Freezing system
System : Refrigerator
surroundings : water in the refrigerator
enthalpy change : Endothermic
C) Sweat evaporating
System : Human being
surroundings : Air nearby
Enthalpy change : exothermic
D) Chemical Hand-warmer
system : Hand warmer pack
Surroundings : human palms
Enthalpy Change : Exothermic
Explanation:
A) Wood burning
system : Wood
surroundings : atmosphere
Enthalpy : Exothermic
This system give away energy to its surroundings hence its enthalpy change is exothermic
B) Water Freezing system
System : Refrigerator
surroundings : water in the refrigerator
enthalpy change : Endothermic
The system absorbs heat from what is put inside(surroundings ) of it hence this is na endothermic system
C) Sweat evaporating
System : Human being
surroundings : Air nearby
Enthalpy change : exothermic
This is an exothermic reaction ( enthalpy change ) because the system gives out heat to the surrounding
D) Chemical Hand-warmer
system : Hand warmer pack
Surroundings : human palms
Enthalpy Change : Exothermic
There is movement of heat from the system to the surrounding hence it is an exothermic reaction
An organic compound which has the empirical formula CHO has an approximate
molar mass of 145 g/mol. What is its probable molecular formula?
Answer:
Molecular formula => C₅H₅O₅
Explanation:
From the question given above, the following data were obtained:
Empirical formula = CHO
molar mass of compound = 145 g/mol
Molecular formula =?
The molecular formula of the compound can be obtained as follow:
Molecular formula = Empirical formula × n
Molecular formula = [CHO]ₙ
[CHO]ₙ = 145
[12 + 1 + 16]n = 145
29n = 145
Divide both side by 29
n = 145 / 29
n = 5
Molecular formula = [CHO]ₙ
Molecular formula = [CHO]₅
Molecular formula => C₅H₅O₅
Please help me l don’t understand please !!!!!!
Answer: C
Explanation:
he never had evidence in the first place that was nearly enough.