Answer:
I am sure it is D or C. have a nice day
Answer:
709 (With sig figs)
Explanation:
Pressure(1) * volume(1) = Pressure(2) * volume(2)
771.75 mm Hg * unknown = 874.27 mm Hg * 626 mL
771.75 mm Hg * unknown = 547,293.02 mm Hg*mL
Divide both sides by 771.75 mm Hg
Unknown = 709 (With sig figs)....709.158432 (without sig figs)
Answer:
A. -163.96kJ
B. -158.34kJ
Explanation:
Heat of combustion is the heat released when an element with oxygen at stp.
Reaction for the combustion of carbon:
C(s) + O2(g) --> CO2(g)
Enthalpy heat of combustion, C (using Hess law) = -393.5 kJ/mol
m = 5g
Molecular weight = 12 g/mol
No of moles = mass/molecular weight
= 5/12
= 0.417mol
DH = -393.5 * 0.417
= -163.96 kJ
B. Heat absorbed by the calorimeter = heat evolve by combustion
= mCH2ODT + mCcDT
Where CH2O is the specific heat capacity of the water in the calorimeter
Cc is the specific heat capacity of copper calorimeter
= (2500*4.184*14.1) + (2000*0.385*14.1)
= -158343J
= -158.34kJ
Answer:
The human eye can only see white visible light and it contains all the colors of the rainbow, from red to violet.
Explanation:
But visable light comes in many "colors" such as radio, infrared, ultraviolet, X-ray, and gamma-ray that are invisible to the naked eye.The reason that the human eye can see the spectrum is because those specific wavelengths stimulate the retina in the human eye.
Answer: 
Explanation:
Firstly, we have to find the Molecular mass of potassium oxide (
):
atomic mass: 39 u
atomic mass: 16 u
molecular mass: 
This means that in 1 mole of there are 
and we need to find how many moles there are in 
:
1 mole of ----- of
----- of
This is the quantity of moles in 73.9 g of potassium oxide
Now we can calculate the number of atoms in 73.9 g of potassium oxide by the following relation:
Where:
is the number of atoms in 73.9g of potassium oxide
is the Avogadro's number, which is determined by the number of particles (or atoms) in a mole.
Then:
This is the quantity of atoms in 73.9g of potassium oxide
