Answer: 72 grams of
are needed to completely burn 19.7 g 
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number
of particles.
To calculate the number of moles, we use the equation:

Putting in the values we get:


According to stoichiometry:
1 mole of
requires 5 moles of oxygen
0.45 moles of
require=
moles of oxygen
Mass of 
72 grams of
are needed to completely burn 19.7 g 
Answer:
cerium (iii) sulfate is less soluble
(0.48 gram) x (1mole / 4.0 gram) = 0.48/4.0 = 0.12 mole
Answer:
Conservation of Energy and Mass
The law of conservation of mass states that in a chemical reaction mass is neither created nor destroyed. ... Similarly, the law of conservation of energy states that the amount of energy is neither created nor destroyed.
Answer:
Molarity = 0.4M
Explanation:
Molar mass of NaOH (M)= 40
m= 8g, V= 500ml=0.5L
n= m/M=[8/40]= 0.2mol
Applying
n= CV
0.2= C×0.5
C= 0.4M