An endothermic chemical reactions products tend to have a higher potential energy than the reactants. Thus making the /\ H positive, not negative.
C.
This is basically the definition of percent composition which is how much mass a element contributes to a specific molecule.
Tbh I would pick A because the liquid* decreases. B doesn’t increase
Answer:
4KO₂ + 2CO₂ -> 2K₂CO₃ + 3O₂
<u> Step 1: Find the moles of O₂.</u>
n(O₂) = mass/ Mr.
n(O₂) = 100 / 32 = 3.125 mol
<u>Step 2: Find the ratio between KO₂ and O₂.</u>
<u>KO₂ </u> : <u> O₂</u>
4 : 3
4/3 : 1
(4*3125)/3 : 3.125
=4.167 mol of KO₂
Thus now we know, to produce 100 g of O₂, we need 4.167mol of KO₂
<u>Step 3: Find the mass of KO₂:</u>
<u />
mass = mol * Mr. (KO₂)
Mass = 4.167* 71.1
Mass = 296.25 g
An isotope has the same number of <em>protons</em> but a different number of <em>elec</em><em>tro</em><em>n</em><em>s</em><em> </em>than others atom of the same element