molarity of a solution means mols per liter.
First, you need to convert 23 grams on NaCl into mols. 23g divided by molar mass (58.44g/mol) which gives you .394 mols.
Now, you need to convert 500ml to L which moves the decimal three places to the left, giving you .500L of solution.
Finally, divide the mols over solution to get .787M
Answer:
Option-D: 2.3 × 10⁻³ mol/dm³
Explanation:
Calculate moles of ascorbic acid,
Moles = Mass / M.Mass
Moles = 0.080 g / 176 g/mol
Moles = 0.00045 mole
Also,
Molarity = Moles / Vol. in dm³
Molarity = 0.00045 mol / 0.20 dm³
Molarity = 0.00227 mol.dm⁻¹ or 2.3 × 10⁻³ mol/dm³
You have to calculate the oxidation estates of the atoms in each compound.
I will start with K2Cr2O7 because I believe that Cr is the best candidate to reduce its oxidation number in 3 units.
In K2Cr2O7:
- K has oxidation state of 1+, then K2 has a charge of 2* (1+) = 2+.
- O has oxidation state of 2*, then O7 has a charge of 7* (2-) = 14-.
That makes that Cr2 has charge of 14 - 2 = +12, so each Cr has +12/2 = +6 oxidation state.
In Cr2O3:
- O has oxidation state of 2-, then O3 has charge 3 * (2-) = - 6
- Then, Cr2 has charge 6+, and each Cr has charge 6+ / 2 = 3+.
So, we have seen that Cr reduced its oxidation state in 3 units, from 6+ to 3+.
Answer: Cr has a change in oxidation number of - 3.
No, it is very unlikely for that to happen.
Answer: 
Explanation:
Depression in freezing point is given by:
= Depression in freezing point
i= vant hoff factor = 1 (for non electrolyte like urea)
= freezing point constant = 
m= molality
Weight of solvent (X)= 950 g = 0.95 kg
Molar mass of non electrolyte (urea) = 60.06 g/mol
Mass of non electrolyte (urea) added = ?
Thus urea was dissolved.
