Answer:
E = 9.95×10⁻¹⁹ J
Explanation:
Given data:
Wavelength = 2×10⁻⁷ m
Energy of photon = ?
Solution:
Formula:
E = hc/λ
h = 6.63×10⁻³⁴ Js
c = 3×10⁸ m/s
by putting values,
E = 6.63×10⁻³⁴ Js × 3×10⁸ m/s / 2×10⁻⁷ m
E = 19.89×10⁻²⁶Jm / 2×10⁻⁷ m
E = 9.95×10⁻¹⁹ J
Answer:
In simple terms, the endothermic reactions absorb energy from the surrounding that is in the form of heat. On the other hand, an exothermic reaction releases energy into the surrounding of the system. A popular example of an endothermic chemical reaction is photosynthesis.
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Answer:
B. They are dimensionless ratios of the actual concentration or pressure divided by standard state concentration, which is 1 M for solutions and 1 bar for gases.
Explanation:
Activity of a substance is defined as the ratio of an effective concentration or an effective pressure to a standard state pressure or a standard state pressure. It is usually a unit less ratio.
Concentrations in an equilibrium constant are really dimensionless ratios of actual concentrations divided by standard state concentrations. Since standard states are 1 M for solutes, 1 bar for gases, and pure substances for solids and liquids, these are the units to be used.
Hence, activity is a fudge factor to ideal solutions that correct the true concentration. Activity of a gas and solute concentration is a ratio with no unit.