Heat of Fusion is defined as the energy required to turn a liquid into a solid, or said phase changing latent heat. In this case the only choice that represents that phase change is (1). Where the heat removed to turn a liquid of a substance into it's solid form is instead added to excite the bonds and liquify it. Yet, heat of fusion (s) ->(l)
is still the same as going from liquid to solid just one is adding and the other is removing, respectively.
Answer:
Explanation:
As per the law of conservation of mass all the mass of carbon present in the hydrocarbon weighing 112 g is present in the 328.5 g of carbon dioxide produced when the hydrocarbon was burned in air.
<u>1) Calculate the mass of carbon in 328.5 g of carbon dioxide</u>:
- Chemical formula of carbon dioxide: CO₂
- Molar mass of CO₂: 12.011 g/mol + 2 × 15.999 g/mol = 44.009 g/mol
x / 328.5 g CO₂ = 12.011 g C / 44.009 g/mol ⇒ x = 86.65 g C
<u>2) Calculate the percent mass of carbon:</u>
- % = (mass of carbon / mass of carbon dioxide) × 100 =
= (89.65 / 112) × 100 = 80.04%
Round to three signifcant figures: 80.0%.
One minus two equals negative one and three minus five equals negative two
Answer:
Magnesium oxide
Explanation:
When magnesium reacts with oxygen, the magnesium atoms donate electrons to O2 molecules and thereby reduce the oxygen. Magnesium therefore acts as a reducing agent in this reaction. The O2 molecules, on the other hand, gain electrons from magnesium atoms and thereby oxidize the magnesium.
