Answer:
Hz
Explanation: Recall the formula for the speed of light is

where
is the speed of light,
is the wavelength, and
is the frequency. Assuming this takes place in a vacuum,
m/s. Now we can solve for frequency



(rounding to 3 sig figs)
Thus, the frequencyis
Hz.
Molar mass of Al₂(CrO₄)₃ is the mass of one mole of Al₂(CrO₄)₃
one mol =weight of Al₂(CrO₄)₃ in g /one mol
1) We have to find the atomic mass (in a periodic talbe) of the following elements (in u)
Al=26.98 u
Cr=52 u
O=16 u
2)We calculate the atomic weight of Al₂(CrO₄)₃
Atomic weight (Al₂(CrO₄)₃)=2(26.98 u)+3[(52 u)+4(16 u)]=
=53.96 u+3(52 u+64 u)=53.96 u+3(116 u=53.96 u+348 u=401.96 u
3) One mole of (Al₂(CrO₄)₃ ) have 401.96 g of Al₂(CrO₄)₃
molar mass=401.96 g/ mol
answer: 401.96 g/ mol
1.97moles
106.7/(1.01x2+16)/3x1 = 1.97