It’s positive when you use energy for work
Answer:
8.3
Explanation:
pH is the measure of the H+ or H30 (they r the same thing) ions in a solution. it is equal to -log[H+]. [H+]= Molar concentration of H+ ions.
Answer:
11 electrons
Explanation:
The atomic number of sodium is 11. This tells us that sodium has 11 protons and because it is neutral it has 11 electrons. The mass number of an element tells us the number of protons AND neutrons in an atom (the two particles that have a measurable mass).
Answer:
They all belong to the p block in the periodic table
Explanation:
Let us examine the electronic configuration of each element;
Oxygen - [He] 2s2 2p4
Silicon - [Ne] 3s2 3p2
Selenium - [Ar] 4s2 3d10 4p4
A common thread that joins all the elements listed above is that they all belong to the p-block in the periodic table. They could be collectively referred to as p-block elements.
Answer:
the molarity is 3.68 moles/L
Explanation:
the molality of the solution of sucrose is
m= moles of glucose / Kg of solvent (water)= 6.81 ,
since the molecular weight of glucose is 180.156 gr/mole , then per each kilogram of solvent there is
6.81 moles*180.156 gr/mole + 1000 gr of water = 2226.86 gr of solution
from the density
volume of solution = mass of solution/density = 2286.86 gr / 1.2 gr/ml = 1855.71 ml
therefore there is 1000 gr of water in 1855.71 ml
then the molarity M is
M= moles of glucose / L of solution = (moles of glucose / Kg of solvent) * (Kg of solvent/L of solution) = 6.81 moles/Kg * 1Kg/1.85 L = 3.68 moles/L
M= 3.68 moles/L
Note:
- Would be wrong in this case to assume density of water = 1 Kg/L since the solution is heavily concentrated in glucose and therefore the density of water deviates from its pure value.
