Answer:
3.11 mol/kg
Explanation:
Molality M = number of moles of solute, n/mass of solvent, m
To calculate the number of moles of glycerol (C₃H₈O₃) in 22.75 g of glycerol, we find its molar (molecular) mass, M',
So, M' = 3 × atomic mass of carbon + 8 × atomic mass hydrogen + 3 × atomic mass of oxygen
= 3 × 12 g/mol + 8 × 1 g/mol + 3 × 16 g/mol = 36 g/mol + 8 g/mol + 48 g/mol = 92 g/mol.
So, number of moles of glycerol, n = m'/M' where m' = mass of glycerol = 22.75 g and M' = molecular mass of glycerol = 92 g/mol
So, n = m'/M'
n = 22.75 g/92 g/mol
n = 0.247 mol
So, the molality of the solution M = n/m
Since m = mass of ethanol = 79.6 g = 0.0796 kg, substituting the value of n into the equation, we have
M = 0.247 mol/0.0796 kg
M = 3.11 mol/kg
So, the molality of the solution is 3.11 mol/kg.
Answer: The frequency of the green light emitted by a hydrogen atom with a wavelength of 546 nm is 
.
Explanation:
Given: Wavelength = 546 nm 
= 
The relation between frequency and wavelength is as follows.
where,
= frequency
c = speed of light = 
= wavelength
Substitute the values into above formula as follows.
Thus, we can conclude that the frequency of the green light emitted by a hydrogen atom with a wavelength of 546 nm is .
Answer:
<h3>The answer is 1.03 g/cm³</h3>
Explanation:
The density of a substance can be found by using the formula
From the question
mass = 257.3 g
volume = 250 cm³
We have
We have the final answer as
<h3>1.03 g/cm³</h3>
Hope this helps you
Both transition metals and alkali metals are good conductors of heat and electricity, react with water, and are easily oxidized.
<h3>What are alkali metals and transition metals?</h3>
The alkali metals are elements of group 1 which are lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). They are also known as the s-block elements because they have their outermost electron in an s-orbital.
The alkali metals are shiny, soft, highly reactive metals and readily lose their outermost electron to create cations with charge +1. They can tarnish rapidly in the air due to oxidation by atmospheric moisture and oxygen.
Transition elements or transition metals are elements that have partially filled d-orbitals. An element having a d-subshell that is partially filled with electrons or can form stable cations with an incompletely filled d orbital.
Any element present in the d-block of the modern periodic table which consists of groups 3 to 12, is considered to be a transition element. For example, the mercury in the +2 oxidation state, corresponds to an electronic configuration of (n-1)d¹⁰. Many paramagnetic compounds are formed by transition metals because they have unpaired electrons in the d orbital.
Learn more about transition metals and alkali metals, here:
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