Assume the molar absorptivity (ε) for CoCl42- at 700 nm is 409.7 M-1 cm-1. If d, the cell path length, is equal to 1.48 cm for the cuvettes being used, and if the measured absorbance (A) at 700 nm is 1.147, what is [CoCl42-]?

1.89 × 10⁻³ M

Explanation:

In a UV Visible Spectrometer, we can determine the concentration of a species using Beer-Lambert law.

A = ε × l × c

where,

We can find  [CoCl₄²⁻] from this expression.

A = ε × l × c

c = A / ε × l

c = 1.147 / 409.7 M⁻¹ cm⁻¹ × 1.48 cm

c = 1.89 × 10⁻³ M

answer: option (4) is the correct answer.

explanation:

areas which are at low altitudes and near the equator tend to receive direct sunlight from the sun. hence, heat energy or radiations from the sun make these areas warmer and they have warmest water.

whereas areas which are at high altitudes and away from the equator do no receive direct sunlight. hence, no direct contact from the sun makes these regions colder and thus, they have colder water.

thus, we can conclude that the statement areas at low latitudes near the equator have the warmest water because they receive the most direct sunlight best explains the relationship between an area's geography and the temperature of its surface water.

a is the correct answer