Answer:
There are five signs of a chemical change:
Colour Change.
Production of an odour.
Change of Temperature.
Evolution of a gas (formation of bubbles)
Precipitate (formation of a solid).
A reaction in which energy is absorbed from the surroundings is called anendothermic<span> reaction. In </span>endothermic<span> reactions the enthalpy of the products is greater than the enthalpy of the reactants. Because reactions release or absorb energy, they affect the temperature of their surroundings.
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Answer:
1.16 moles CO₂
Explanation:
To find the moles of CO₂, you need to (1) convert grams C₈H₁₈ to moles (via the molar mass) and then (2) convert moles C₈H₁₈ to moles CO₂ (via the mole-to-mole ratio from equation coefficients). It is important that the conversions/ratios are arranged in a way that allows for the cancellation of units. The final answer should have 3 significant figures like the given value.
Molar Mass (C₈H₁₈): 8(12.011 g/mol) + 18(1.008 g/mol)
Molar Mass (C₈H₁₈): 114.232 g/mol
2 C₈H₁₈ + 25 O₂ -----> 16 CO₂ + 18 H₂O
^ ^
16.6 g C₈H₁₈ 1 mole 16 moles CO₂
-------------------- x ----------------- x ------------------------- = 1.16 moles CO₂
114.232 g 2 moles C₈H₁₈
A flame test is an analytic procedure used in chemistry to detect the presence of certain elements. :)
