Answer:
Explanation:
To convert from representative particles to moles, Avogadro's Number: 6.02*10²³, which tells us the number of particles (atoms, molecules, etc.) in 1 mole of a substance.
We can use it in a ratio.
Multiply by the given number of molecules.
Flip the ratio so the molecules of water cancel out.
Divide.
The original number of molecules has 2 significant figures: 3 and 1, so our answer must have the same. For the number we calculated, that is the tenth place. The 4 in the hundredth place tells us to leave the 1.
There are about 5.1 moles of water in 3.1*10²⁴ molecules of water.
The answer is Na < Cl
Chlorine is more electronegative than sodium because this follows the trend of the periodic table. The trend states that an element's electronegativity increases from left to right of a period and bottom to up of a group. Since sodium and chlorine are from the same period, and chlorine is at the right of sodium, chlorine is more electronegative.
Answer:
Solution is 4.67% by mass of salt
Explanation:
% by mass is the concentration that defines the mass of solute in 100g of solution.
In this case we have to find out the mass of solution with the data given:
Mass of solution = Mass of solute + Mass of solvent
Solute: Salt → 14.2 g
Solvent: Water → 290 g
Solution's mass = 14.2 g + 290g = 304.2 g
% by mass = (mass of solute / mass of solution) . 100
(14.2 g / 304.2g) . 100 = 4.67 %
Answer:
1.25mole of Mg(OH)₂
Explanation:
The reaction is between Mg(OH)₂ and HCl, this is a neutralization reaction between an acid and a base.
Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O
The balanced reaction equation is given above.
2 mole of HCl reacts with 1 mole of Mg(OH)₂
So, 2.5mole of HCl will react with 
= 1.25mole of Mg(OH)₂
The number of moles of Mg(OH)₂ is given as 1.25mol
Answer:
neq N2O4 = 0.9795 mol.....P = 0.5 atm; T = 25°C
Explanation:
ni change eq.
N2O4 1 1 - x 0.8154.....P = 1 atm; T = 25°C
NO2 0 0 + x x
∴ x = neq = Peq.V / R.T.....ideal gas mix
if P = 0.5 atm, T = 25°C; assuming: V = 1 L
⇒ x = neq = ((0.5 atm)(1 L))/((0.082 atm.L/K.mol)(298 K))
⇒ x = neq = 0.0205 mol
⇒ neq N2O4 = 1 - x = 1 - 0.0205 = 0.9795 mol
