Expression for the Balmer series to find the wavelength of the spectral line is as follows:
1 / λ = R
Where, λ is wavelength, R is Rydberg constant, and n is integral value (4 here → Fourth level)
Substitute 1.097 x 10⁷ m⁻¹ for R and 4 for n in the above equation
1 / λ = (1.097 x 10⁷ m⁻¹)
= 0.20568 x 10⁷ m⁻¹
λ = 4.86 x 10⁻⁷ m
since 1 m = 10⁹ nm
λ = 486 nm
Ca ionises into Ca^2+. Ca^2+ will be attracted to O^2- ions in the water, since opposite charges attract. (Hydrogen in water forms H^+)
Answer:
The empirical formula of a compound is Na2Cr2O7
Explanation:
Empirical formula is defined as the lowest ratio of elements present in any substance. In order to determine the empirical formula for a substance containing these elements we have to follow some steps.
1.In the first step, we have to divide the given mass of an element with its molecular mass to convert the mass to moles.
Similarly, the moles of Cr and O in that compound were calculated and found as 0.396 and 1.3875, respectively.
2. Then the next step is to determine the lowest moles and divide all the moles with that lowest mole. As here the lowest mole is 0.396. So on dividing the moles of Na, Cr and O with 0.396, we will obtain the ratio as 1:1:3.5.
3. As the ratio consists of a fractional number, we have to multiply it with the smallest possible integer to convert it to whole number. In this case, if we multiply it with 2 , we will get the ratio as 2:2:7.
Thus, the empirical formula for the compound can be written as Na2Cr2O7.
If you draw or search for the molecular geometry of NOCl, you would know that it has a bent shape. This bent shape is a characteristic of a polar molecule. The dominant intermolecular forces for polar compounds is the <em>dipole-dipole force</em>.
Answer:
<em>249 kJ</em>
Explanation:
To obtain the energy change of the reaction:
H₂O → H₂ + ¹/₂ O₂
It is necessary to obtain the difference between bond energy of the products and bond energy of the reactant, thus:
Energy of products:
1 mol of H-H bond × 436 kJ/mol = 436 kJ
¹/₂ mol of O=O bond × 498 kJ/mol = 249 kJ
Energy of reactant:
2 mol of H-O bond × 467 kJ/mol = 934 kJ
Energy change of the reaction is:
934 kJ - (436 kJ + 249 kJ) = <em>249 kJ</em>
<em></em>
I hope it helps!
