Molecular mass of H2O is: 16+2*1=18
so moles of 40g of H2O is: 40/18=2.22
Answer:
P' = 41.4 mmHg → Vapor pressure of solution
Explanation:
ΔP = P° . Xm
ΔP = Vapor pressure of pure solvent (P°) - Vapor pressure of solution (P')
Xm = Mole fraction for solute (Moles of solvent /Total moles)
Firstly we determine the mole fraction of solute.
Moles of solute → Mass . 1 mol / molar mass
20.2 g . 1 mol / 342 g = 0.0590 mol
Moles of solvent → Mass . 1mol / molar mass
60.5 g . 1 mol/ 18 g = 3.36 mol
Total moles = 3.36 mol + 0.0590 mol = 3.419 moles
Xm = 0.0590 mol / 3.419 moles → 0.0172
Let's replace the data in the formula
42.2 mmHg - P' = 42.2 mmHg . 0.0172
P' = - (42.2 mmHg . 0.0172 - 42.2 mmHg)
P' = 41.4 mmHg
Explanation:
The nitrogen dioxide is a covalent compound where one nitrogen is the central atom which is bonded to two oxygen atoms, where one oxygen atom is bonded by a single bond and other oxygen atom by a double bond.
The correct statement is " A single bond, because they overlap orbitals to share one pair of electrons." A fluorine atom is unstable with 7 electrons in its valence shell and so needs one more electron to achieve stability. This is according to the octet rule which states that an atom will gain or lose electrons until there are 8 electrons in its valence shell. So each fluorine donates an electron to form a single pair and the 
achieves a noble gas configuration.
Answer:
0.11M
Explanation:
What is the Molarity of a Ca(OH)2 solution if 30.0mL of
the solution is neutralized by 26.4mL of 0.25M HCI solution?
1L (1000 ml) of the HCl contains 0.25 moles of H ion
26.4 ml contains ( 26.4 X0.25/1000) moles of H ion ion
=0.0066 moles H ion
2HCl +Ca (OH)2-----> 2H2O +CaCl2
SO 2 H IONS NEUTRALIZE 1 Ca(OH)2 MOLECULE
00066 moles H ion neutralize 0.0033 moles Ca(OH)2
the 0.0033 moles are distributed over 30 ml, so the concentration of the
Ca(OH)2 IS 0,0033/(30/1000) =0.11 moles/liter or 0.11M
