A chemical engineer must report the average volume of a certain pollutant produced by the plants under her supervision. Here are

Answer:

To break a single I-I bond, the wavelength of light required is 7.92 × 10⁻⁷ m

Explanation:

The energy needed to break one mole of iodine-iodine single bonds is 151 KJ

The energy necessary to rupture one iodine-iodine bond is calculated as (151 KJ/mol) / 6.02 × 10²³/mol = 2.51 × 10⁻²² KJ

or

2.51 × 10⁻¹⁹ J

Formula:

E = hc / λ    

Where h is Planck's constant    = 6.626 × 10⁻³⁴ js

c is the speed of light = 3 × 10⁸ m/s

λ = wavelength

Solution:

E = hc / λ  

λ   = hc / E

λ   =  (6.626 × 10⁻³⁴ js × 3 × 10⁸ m/s ) / 2.51 × 10⁻¹⁹ J

λ   = 19.878 × 10⁻²⁶ j.m / 2.51 × 10⁻¹⁹ J

λ   = 7.92 × 10⁻⁷ m

The answer is actually 3, believe me.

Explanation:

A total of 0.0222 moles of NaOH are necessary to react with NH4F. \nBased on the reaction NH4F + NaOH --> NaF + NH3 + H2O, we start with: \nMass of NH4F = 0.821 g, NaOH concentration = 1 M, volume of NaOH = 25 mL. \nTo find moles: moles of NaOH = (CV)/1000. Thus, moles of NaOH = (1 * 25)/1000 = 0.025 moles of NaOH used. \nThe molar mass of NH4F is 37 g/mol, making moles of NH4F = 0.821 / 37 = 0.0222 moles. \nThis shows that NaOH is in excess, with 0.025 - 0.0222 = 0.0028 moles of NaOH remaining. Hence, 0.0222 moles of NaOH are needed to react with NH4F.