Answer: Please see answer below
Explanation:
Mecury vapor lamp is better to use than Sodium vapor light, this is because because
---The Filaments of the lamp in sodium emit fast moving electrons, which causes valence electrons of the sodium atoms to excite to higher energy levels which when electrons after being excited, relax by emitting yellow light which concentrates on the the monochromatic bright yellow part of the visible spectrum which is about 580-590 or about (589nm) which will fall incident on the calibrations making it difficult to see
While
In Mercury vapor lamp, The emitted electrons from the filaments, after having been excited by high voltage, hit the mercury atoms but the excited electrons of mercury atoms relax and emits an ultraviolet uv invisible lights falling on the mecury vapour lamp to produce white light covering a wide range of (380-780 nm) which is visible that is why it is used for calibrations purposes in lightening applications.
✅Show work regardless if student got answer correct or incorrect
q = mC∆T
q = (30.0g)(0.900J/goC)(50oC)
q = 1350 J
So, the right answer is 1350 J
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The arrangement of electron pairs around CH4 and NH3, According to the VSEPR model is the same, because in each case there are the same number of electron pairs around the central atom. So the NH3 and CH4 arrangement of electron pairs is the same because in each case there are the same number of electron pairs around the central atom.
Answer: the pH of the solution is 4.52
Explanation:
Consider the weak acid as Ha, it is dissociated as expressed below
HA H⁺ + A⁻
the Henderson -Haselbach equation can be expressed as;
pH = pKa + log( [A⁻] / [HA])
the weak acid is dissociated into H⁺ and A⁻ ions in the solution.
now the conjugate base of the weak acid HA is
HA(aq) {weak acid} H⁺(aq) + A⁻(aq) {conjugate base}
so now we calculate the value of Kₐ as well as pH value by substituting the values of the concentrations into the equation;
pKₐ = -logKₐ
pKₐ = -log ( 7.4×10⁻⁵ )
pKₐ = 4.13
now thw pH is
pH = pKₐ + log( [A⁻] / [HA])
pH = 4.13 + log( [0.540] / [0.220])
pH = 4.13 + 0.3899
pH = 4.5199 = 4.52
Therefore the pH of the solution is 4.52
