Number of moles of oxygen = x
number of moles of nitrogen = y
x = 2y
initial pressure, p1 = 0.8 atm
final pressure, p2 = 1.10 atm
At constant volume and temperature p1 / n1 = p2 / n2
=> p1 / p2 = n1 / n2
n1 = x + y = 2y + y = 3y
n2 = 0.2 + 3y
=> p1 / p2 = 3y / (0.2 + 3y)
=> 0.8 / 1.10 = 3y / (0.2 + 3y)
=> 0.8 (0.2 + 3y) = 1.10 (3y)
0.16 + 2.4y = 3.3y
=> 3.3y - 2.4y = 0.16
=> 0.9y = 0.16
=> y = 0.16 / 0.9
=. x = 2*0.16/0.9 = 0.356
Answer: 0.356 moles O2
Answer:
145.8g
Explanation:
Given parameters:
Number of moles of magnesium hydroxide = 2.5mol
Unknown:
Mass of Mg(OH)₂ = ?
Solution:
To solve this problem we use the expression below;
Mass of Mg(OH)₂ = number of moles x molar mass
Molar mass of Mg(OH)₂ = 24.3 + 2(16 + 1) = 58.3g/mol
Mass of Mg(OH)₂ = 2.5 x 58.3 = 145.8g
Answer:

Explanation:
Hydrogen bonding:-
Hydrogen bonding is a special type of the dipole-dipole interaction and it occurs between hydrogen atom that is bonded to highly electronegative atom which is either fluorine, oxygen or nitrogen atom.
Partially positive end of the hydrogen atom is attracted to partially negative end of these atoms which is present in another molecule. It is strong force of attraction between the molecules.
Thus, hydrogen must be linked to electronegative atom which is oxygen, fluorine and nitrogen which is in
and thus, it will shown hydrogen bonding.
You start by diving each quantity given by the atomic wight of each element:
Phosphorus (P) 
Hydrogen (H) 
Then you divide by the lowest number:
for phosphorus
for hydrogen
So the empirical formula will be:
