Answer: C.) It burns and causes lung cancer
1) Calcium carbonate contains 40.0% calcium by weight.
M(CaCO₃)=100.1 g/mol
M(Ca)=40.1 g/mol
w(Ca)=40.1/100.1=0.400 (40.0%)!
2) Mass fraction of this is excessive data.
3) The solution is:
m(Ca)=1.2 g
m(CaCO₃)=M(CaCO₃)*m(Ca)/M(Ca)
m(CaCO₃)=100.1g/mol*1.2g/40.1g/mol=3.0 g
Answer:
D. As white light passes through a prism , it bends and separates into different colors
Explanation:
When light enters a prism, it experiences a phenomenon called 'refraction'.
Refraction occurs when light crosses the interface between two mediums with different optical density; when this happens, the light bends and also changes speed.
The angle at which the ray of light is refracted into the second medium depends on the optical density of the two mediums, but also on the wavelength of the light.
In particular, longer wavelengths (red color) are refracted the least, while shorter wavelengths (violet color) are refracted the most.
As a result, when white light (consisting of all the colors of visible light) enters into a prism, they different wavelengths are separated: therefore, white light separates into different colors.
So, the correct answer is
D. As white light passes through a prism , it bends and separates into different colors
The <span>simple machine found on the head of the ax is </span>Wedge. A wedge is an inclined plane that can be moved. When an ax is used
to split wood, the ax handle
exerts a force on the blade of
the axe, which is the wedge. That force pushes the wedge
down into the wood. The wedge in turn exerts an
output force splitting the wood in two.
Answer:
a=28600J; b=90.6 J/K; c=402 torr
Explanation:
(a) considering the data given
Vapour pressure P1 =0 at Temperature T1 = 42.43˚C,
Vapour pressure P2 = 273.15 at Temperature T2= 315.58 K)
Using the Clausius-Clapeyron Equation
ln (P2/P1) = (ΔH/R)(1/T2 - 1/T1)
In 760/140 = ΔH/8.314 J/mol/K × (1/315.58K -- 1/273.15K)
ΔH vap= +28.6 kJ/mol or 28600J
(b) using the Equation ΔG°=ΔH° - TΔS to solve forΔS.
Since ΔG at boiling point is zero,
ΔS =(ΔH°vap/Τb)
ΔS = 28600 J/315.58 K
= 90.6 J/K
(c) using ln (P2/P1) = (ΔH/R)(1/T2 - 1/T1)
ln P298 K/1 atm = 28600 J/8.314 J/mol/K × (1/298.15K - 1/315.58K)
P298 K = 0.529 atm
= 402 torr
