Answer:
Explanation:
When we react Hydrochlorid Acid with zinc we have the following reaction:
2HCl(aq) + Zn(s) --> ZnCl2(aq) + H2(g)
The hydrogen gas formed is lost to the environment, so we can affirme that in the start we have the mass for all the H, Cl and Zn atoms in the solution, but after the reaction occurs, we have only the mass for the Cl and Zn atoms.
That's why the mass is less than the original.
The law that the student was told is only applied to closed environments.
Answer:
λ=2167.6 nm
The wavelength of light emitted is 2167.6 nm.
Explanation:
We recall that Eₙ=
since there was transition from n7 to n=4 we will first calculate the change in the energy i.e ΔE
ΔE=E₄-E₇
ΔE=
ΔE=-9.1760*10^-20 J
Now:
|ΔE|=Energy of photon=h*v=h*c/λ
λ=h*c/|ΔE|
λ=
λ=2.1676*10^-6 m
λ=2167.6*10^-9 m
λ=2167.6 nm
The wavelength of light emitted is 2167.6 nm.
Answer:
Ok, so the process here is to convert the mass of H2 (hydrogen gas) to moles by dividing the mass by the molar mass of H2. Once you have the moles then you have to multiply by the STP (standard temperature and pressure) molar volume which should be 22.4.
Molar mass of H2 = (1.01)x2 = 2.02g/mol
19.3/2.02 = 9.55 moles
Now just multiply the moles by the molar volume
9.55 moles x 22.4 = 213.92 Litres of H2 are in 19.3g of H2
Answer:
True.
Explanation:
An exothermic reaction has a positive enthalpy (heat) of reaction. However, it can be negative in some circumstances.
