Answer:
477 nm
Explanation:
Using the expression for the energy as:
Where,
h is Plank's constant having value
c is the speed of light having value
is the wavelength of the light
Given,
Also, 
So, Energy for one atom = 
Thus, applying values as:


( 1 m =
nm )
1. The reaction for this would be:
Sn + 4 HNO₃ → SnO₂ + 4 NO₂ + 2 H₂O
The first observation would be bubbling of the solution and brown acrid smoke is produced due to the presence of NO₂ gas. Another observation would be the presence of a white solid which is SnO₂.
2. Heating was required to get rid of the H₂O. When all moisture is gone, you weigh the sample. Afterwhich, you further heat it to get ride of the oxygen. By doing this, you would know the individual mass of each element. Then, you can solve for the empirical formula of the oxide of tin.
The molality of solution = 1.576
<h3>Further explanation</h3>
Given
6.75% solution of ethanol in water
Required
The molality
Solution
Assume 100 g solution ,
Ethanol = 6.75 g⇒solute
Water = 93.25 g = 0.09325 kg⇒solvent
<em>Molality = mol solute/kg solvent</em>
mol Ethanol(MW=46 g/mol) :

the molality :

Answer:
Explanation:
38736 ÷ 4784 = 8.097
Sig Figs
4
8.097
Decimals
3
8.097
Scientific Notation
8.097 × 10^0
E-Notation
8.097e+0
Words
eight point zero nine seven
Answer:
Jane has 2.77 * 10^20 molecules cholesterol in 1 dL of blood
Explanation:
<u>Step 1:</u> Given data
Molar mass of Cholesterol = 386.654 g/mol
Jane has a cholesterol of 178 mg/dL
<u>Step 2:</u> Calculate mass of cholsterol in 1 dL
178 mg/dL means in 1 dL she has 178 mg cholesterol or 0.178 grams
<u>Step 3</u>: Calculate number of moles of cholesterol
Number of moles = mass of cholesterol / molar mass of cholesterol
Number of moles = 0.178 grams / 386.654 g/mol = 4.6 * 10^-4 moles
<u>Step 4: </u>Calculate number of molecules
Number of molecules = 4.6 * 10^-4 mol * 6.022 *10^23 / mol = 2.77 * 10^20 molecules
Jane has 2.77 * 10^20 molecules cholesterol in 1 dL of blood