Answer:
(a) Hypoeutectic
(b) Alpha solid, aluminium
(c) 70% α
, 30% β
(d) 97.6% α, 2.4% β
(e) 97.6% α, 2.4% β
(f) 97% α, 3% β
Explanation:
(a) The eutectic composition for Al Si alloy is 11.7 wt% silicon, therefore, an Al-4% Si alloy is hypoeutectic
(b) For the hypoeutectic alloy, aluminium, Al, is expected to form first, such that the aluminium content is reduced till the point it gets to the eutectic proportion of 11.7 wt% silicon
(c) At 578°C we have
% α: Al (11 - 4)/(11 - 1) = 70% α
% L: Si 100 - 70 = 30% β
(d) At 576°C we have
α: 99.83% Si (99.83 - 4)/(99.83- 1.65) = 97.6% α
β: 1.65% Si (4 - 1.65)/(99.83- 1.65) = 2.4% β
(e) Primary α: 1.65% α (99.83 - 4)/(99.83 - 1.65) = 97.6% α
Eutectic 4% Si = 100 - 97.6 = 2.4% β
(f) At 25°C we have;
α%: (99.83 - 4)/(99.83 - 1) = 97% α
β%: 100 - 97 = 3% β.
Answer:
The molecules inside the ice pack are frozen therefore they are stuck in place. The molecules inside an insulated cup aren't frozen but still stuck inside of their container so that they can not fly out.
Explanation:
The molecular formula is calculated as follows
that is for carbon = 26.7/12= 2.23 moles
hydrogen= 2.24/1=2.24 moles
oxygen= 71.1/16=4.44 moles
<h3> What is molecular formula?</h3>
A chemical formula is a way to describe the chemical ratios of the atoms that make up a specific chemical compound or molecule in chemistry. Chemical element symbols, numbers, and occasionally other symbols, such as parentheses, dashes, brackets, commas, and plus (+) and minus () signs, are used to represent the chemical elements. These can only include one typographic line of symbols, which may also include subscripts and superscripts. A chemical formula has no words and is not the same as the chemical name. A chemical formula does not equal a complete chemical structural formula, despite the fact that it may suggest some basic chemical structures. Chemical formulae are often less powerful than chemical names and structural formulae, and they can only fully describe the structure of the simplest molecules and chemical compounds.
To learn more about molecular formula from the given link:
brainly.com/question/14425592
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Answer:
a. The reaction is endothermic.
Explanation:
The heat involved in a chemical reaction is given by the enthalpy change (ΔH), which is equal to the balance between the chemical bonds that are broken (release energy) and the chemical bonds that are formed (need energy):
ΔH ≅ bonds broken - bonds formed
If broken bonds > bonds formed ⇒ ΔH > 0 ⇒ endothermic reaction
Therefore, the reaction is endothermic (it requires energy).
