Answer:
ν ≈ 4.7 × 10¹⁴ Hz
General Formulas and Concepts:
<u>Chem</u>
Speed of Light = Wavelength times Frequency
Explanation:
<u>Step 1: Define</u>
λ = 6.4 × 10⁻⁷ m
<u>Step 2: Solve for ν </u>
3.0 × 10⁸ = 6.4 × 10⁻⁷ · ν
ν = 4.6875 × 10¹⁴ Hz
<u>Step 3: Check</u>
<em>We are given 2 sig figs. Follow sig fig rules.</em>
4.6875 × 10¹⁴ Hz ≈ 4.7 × 10¹⁴ Hz
Answer: 65.38g of Ca(OH)2 is needed
From The equation of reaction
2 HCl + Ca ( OH ) 2 ⟶ CaCl 2 + 2 H 2 O
NB: Molar mass of HCl= 1+35.5=36.5
Ca(OH)2= 74
From The stoichiometric equation
2mol of HCl(36.5×2=73) require 1mol of Ca(OH)2 (74g)
Hence 64.5g of HCl will require 64.5×74/73= 65.38g of Ca(OH)2
1.54 x 10^-10
thats the answer
A
23.6°C
use delta h method