<span>34.2 grams
Lookup the atomic weights of the involved elements
Atomic weight potassium = 39.0983
Atomic weight Chlorine = 35.453
Atomic weight Oxygen = 15.999
Molar mass KClO3 = 39.0983 + 35.453 + 3 * 15.999 = 122.5483 g/mol
Moles KClO3 = 87.4 g / 122.5483 g/mol = 0.713188188 mol
The balanced equation for heating KClO3 is
2 KClO3 = 2 KCl + 3 O2
So 2 moles of KClO3 will break down into 3 moles of oxygen molecules.
0.713188188 mol / 2 * 3 = 1.069782282 mols
So we're going to get 1.069782282 moles of oxygen molecules. Since each molecule has 2 atoms, the mass will be
1.069782282 * 2 * 15.999 = 34.23089345 grams
Rounding the results to 3 significant figures gives 34.2 grams</span>
Answer : The correct option is, (D) 3600 kJ
Explanation :
Mass of octane = 75 g
Molar mass of octane = 114.23 g/mole
Enthalpy of combustion = -5500 kJ/mol
First we have to calculate the moles of octane.

Now we have to calculate the heat released in the reaction.
As, 1 mole of octane released heat = -5500 kJ
So, 0.656 mole of octane released heat = 0.656 × (-5500 kJ)
= -3608 kJ
≈ -3600 kJ
Therefore, the heat released in the reaction is 3600 kJ
Yes. Everything is made up of mass. If it takes up space, it has mass
Answer:
616,0 ng is the right answer.
Explanation:
You should know that 1 mole = 1 .10^9 nanomoles
Get the rule of three.
1 .10^9 nanomoles ...................... 56.0 gr
11 nanomoles .....................
(11 x 56) / 1 .10^9 nanomoles = 6.16 x 10^-7 gr
Let's convert
6.16 x 10^-7 gr x 1 .10^9 = 616 ngr