Answer:
0.550
Explanation:
The absorbance (A) of a substance depends on its concentration (c) according to Beer-Lambert law.
A = ε . <em>l</em> . c
where,
ε: absorptivity of the species
<em>l</em>: optical path length
A 45 mM phosphate solution (solution A) had an absorbance of 1.012.
A = ε . <em>l</em> . c
1.012 = ε . <em>l</em> . 45 mM
ε . <em>l</em> = 0.022 mM⁻¹
We can find the concentration of the second solution using the dilution rule.
C₁ . V₁ = C₂ . V₂
45mM . 11mL = C₂ . 20.0 mL
C₂ = 25 mM
The absorbance of the second solution is:
A = (ε . <em>l</em> ). c
A = (0.022 mM⁻¹) . 25 mM = 0.55 (rounding off to 3 significant figures = 0.550)
Answer: four hundred and 18
Explanation:
Simple math showed that only 16 words are possible from a two-letter combination, but a three-letter code produces 64 words. Operating on the principle that the simplest solution is often correct, researchers assumed a three-letter code called a codon.
Answer:
Explanation: Sodium Nitroprusside, whose molecular formula is • 2H2O, and whose molecular weight is 297.95. Dry sodium nitroprusside is a reddish-brown powder, soluble in water.
The molar volume, symbol Vm<span>, is the </span>volume occupied by one mole of a substance at a given temperature and pressure. <span>It is equal to the </span>molar<span> mass divided by the mass density. Therefore, we calculate as follows:
Vm(CO2) = 44.01 / 1.56 = 28.21 cm^3 / mol
</span>Vm(NH3) = 17.03 / 0.84 = 20.27 cm^3 / mol
Answer:
Salt
Explanation:
It is because it has a defined composition.
