Answer:
6.6023g
Explanation:
To create a 0.247 M solution required weight of barium hydroxide.
0.247 x 171.346 =42.322g per liter
Therefore required mass for 156g of water = 42.322 x 0.156 = 6.6023g
Answer:
C. AlCl3 is a covalent compound.
Explanation:
It is formed by mutual sharing of electrons between two atoms each contributing equal number of electrons to the electron pair.
The hazard from thalidomide is that it can cause children to die or to be born with deformed limbs, often without limbs. That's why its use has been greatly reduced and is now only usable in treating certain types of cancers or leprosy.
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Answer:
a) The wavelength is around 33.8 nm = 3.38*10⁻¹ nm
b) Ultraviolet
Explanation:
a) The energy (E) of a photon is related to its wavelength (λ) by the Planck's equation:

where h = Planck's constant = 6.626*10^-34 Js
c = speed of light = 3*10^8 m/s
E = 3.55*10^6 J/mol
The energy in terms of J/photon is:

Based on eq(1)
\lambda = h\frac{c}{E}=6.626*10^{-34}Js*\frac{3*10^{8}m/s}{5.89*10^{-18}J}=3.38*10^{-8}m
The wavelength is around 33.8 nm = 3.38*10⁻¹ nm
b) In the electromagnetic spectrum the ultraviolet range extends from 390 nm-8.82 nm
The calculated wavelength of 33.8 nm should fall in the UV range.