Answer:
0.0222 mol KCl
Explanation:
2 KClO3 (s) 2 KCl (s) + 3 O2 (g)
2.73 g x mol
x g KCl = 2.73 g KClO3 x[ (1 mol KClO3)/ (122.5 g KClO3) ] x [(2 mol KCl)/ (2 mol KClO3)]
x g KCl = 0.0222 mol KCl
Answer:
λ = 0. 484 × 10⁻⁸ m
Explanation:
Given data:
Frequency = 6.2 × 10¹⁶ Hz
Wavelength = ?
Solution:
Formula:
Wavelength = speed of light / frequency
speed of light = 3 ×10⁸ m/s
λ = c / f
λ = 3 ×10⁸ m/s / 6.2 × 10¹⁶ s⁻¹
λ = 0. 484 × 10⁻⁸ m
Answer:
1700 kj
Explanation:
The given reaction is exothermic reaction.
Exothermic reaction:
The type of reactions in which energy is released are called exothermic reactions.
In this type of reaction energy needed to break the bonds are less than the energy released during the bond formation.
For example:
Chemical equation:
C + O₂ → CO₂
ΔH = -393 Kj/mol
it can be written as,
C + O₂ → CO₂ + 393 Kj/mol
Chemical equation:
2Al + Fe₂O₃ → Al₂O₃ + 2Fe + 850 Kj
when one mole of Fe₂O₃ react 850 kj energy is produced.
when 2 moles react,
2 × 850 kj = 1700 kj
Answer:
D
Explanation:
If the atom is neutral, the sum of the core and valence electrons is the same as the number of protons, which is the atomic number of the element. So if the sum of the core and valence electrons in a neutral atom equals 25 , that is the number of protons in the atomic nucleus, and the atomic number of the element.
