Answer:
Frequency = 0.005× 10¹⁷ s⁻¹
E = 0.03 × 10⁻²⁰KJ
Explanation:
Given data:
Wavelength of light = 630.0 nm (630 × 10⁻⁹ m)
Frequency of light = ?
Energy in joule = ?
Solution:
speed of light = wavelength × frequency
Frequency = speed of light / wavelength
Frequency = 3 × 10⁸ m/s / 630 × 10⁻⁹ m
Frequency = 0.005× 10¹⁷ s⁻¹
Energy:
E = h. f
E = 6.63× 10⁻³⁴ Kg. m²/s × 0.005× 10¹⁷ s⁻¹
E = 0.03 × 10⁻¹⁷ j
E = 0.03 × 10⁻¹⁷ j×1 kj /1000 j
E = 0.03 × 10⁻²⁰KJ
Answer:
B. - 210 kJ
Explanation:
<em>∵ ΔHrxn = ∑(bond energies)products - ∑(bond energies)reactants.</em>
- The bond formation in the products releases energy (exothermic).
- The bond breaking in the reactants requires energy (endothermic).
The products:
- H₂O contains 2 O-H (- 459 kJ/mol) bonds.
- O₂ contain 1 O=O (- 494 kJ/mol) bond.
The reactants:
- H₂O₂ contain 2 O–H (459 kJ/mol) bonds and 1 O–O (142 kJ/mol) bond.
∵ ΔHrxn = ∑(bond energies)products - ∑(bond energies)reactants.
<em>∴ ΔHrxn = [2 (2 x (O–H bond energy) + (1 x (O=O bond energy)] - 2 [(2 x (O–H bond energy) + (1 x (O–O bond energy)] </em>= [2 (2 x - 459 kJ/mol) + (1 x - 494 kJ/mol)] - 2 [(2 x 459 kJ/mol) + (1 x 142 kJ/mol)] = (- 2330 kJ) + (2120 kJ) = <em>- 210 kJ.</em>
Ionic compounds are formed between oppositely charged ions.
A binary ionic compound is composed of ions of two different elements - one of which is a positive ion(metal), and the other is negative ion (nonmetal).
To write the empirical formula of binary ionic compound we must remember that one ion should be positive and other ion should be negative, then only the correct formula should be written. To write the empirical formula the charges of opposite ions should be criss-crossed.
First empirical formula of binary ionic compound is written between
First Formula would be 
Second empirical formula is between 
Second Formula would be 
Note : When the subscript are same they get cancel out, so
would be written as 
Third empirical formula is between 
Third Formula would be :
Forth empirical formula is between 
Forth Formula would be :
or 
Note- The subscript will be simplified and the formula will be written as
.
The empirical formula of four binary ionic compounds are : 