A phase change is a physical change.
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Answer:
The answer to your question is below
Explanation:
Data
Volume = 1000 ml
Concentration = 2M
molecule = NaCl
Process
1.- Calculate the number of moles of NaCl
Molarity = moles/Volume
-Solve for volume
moles = Molarity x Volume (liters)
-Substitution
moles = 2 x 1
-Result
moles = 2
2.- Determine the molar mass of NaCl
NaCl = 23 + 35.5 = 58.5 g
3.- Calculate the mass of NaCl to prepare the solution
58.5 g ----------------- 1mol
x ----------------- 2 moles
x = (2 x 58.5) / 1
x = 117g
4.- Weight 117 g of NaCl, place them in a volumetric flask (1 l), and add enough water to prepare the solution.
It's called a nebula or nebulae (plural). They are not only massive clouds of dust, hydrogen and helium gas, and plasma; they are also often “stellar nurseries” – i.e. the place where stars are born.
NaCl molar mass 58.4 g/mol
moles of NaCl = .35 g * 1 mol/58.4 g = 0.005993 mol
volume of solution = 150 mL = 0.15 L
molarity = mol/vol(in L)
[NaCl] = 0.005933mol/0.15L = 0.03995 M = 0.040 M
Answer:
B- Iodine
Explanation:
Using the periodic trends, electronegativity (electron affinity) goes down as you go down a period. This is due to the atom gaining new shells when going down each period, resulting in a weakened attraction force between the nucleus and the electrons in the cloud. In other words. as more shells are added, the weaker the atom's affinity for electrons are and the less electronegative it is. As a result, Iodine would have the weakest attraction for electrons in a bond with Calcium as it is the furthest down in the periodic table.
