Answer:
<em>When molecular hydrogen (H2) and oxygen (O2) are combined and allowed to react together, energy is released and the molecules of hydrogen and oxygen can combine to form either water or hydrogen peroxide.</em>
Density = 968 g/cm³
mass = 250 g
Volume = ?
Therefore:
D = m / V
968 = 250 / V
V = 250 / 968 => 0.26 cm³
Answer C
The greatest positive enthalpy change has PCl₅(g) → P(g) + 5Cl(g)
An enthalpy change is difference between the enthalpy after the chemical reaction has completed.
An enthalpy change of phosphorus(V) chloride (PCl₅) molecule is energy needed for breaking up one molecule of phosphorus(V) chloride into one phosphorus and five chlorine atoms.
In a chemical reaction, chemical bonds are forming and breaking and this cause the transformation of one group of chemical substances to another.
Energy is needed to break chemical bonds in molecules (positive enthalpy change), while during formation of molecule, energy is released (negative enthalpy change)
The stronger are the bonds, more energy is needed and enthalpy change is more positive.
PCl₅ has more bonds to break than PCl₃.
More about enthalpy change: brainly.com/question/16387742
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<span> Heterogeneous mixture because the components are not or can't be mixed uniformly..
Ex : Oil in water or Sand in water </span>
