a serving of a particular fruit dessert contains 20.0 g of sugar. if all the sugar is sucrose, c12h22o11, how many molecules of
1 answer:
Taking into account the definition of Avogadro's number and molar mass, 3.49334×10²² molecules of sucrose are present.
<h3>Definition of molar mass</h3>The molar mass of substance is a property defined as its mass per unit quantity of substance, in other words, molar mass is the amount of mass that a substance contains in one mole.
<h3>Avogadro's Number</h3>Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023×10²³ particles per mole. Avogadro's number applies to any substance.
<h3>Molecules of sugar in this case</h3>In first place, the molar mass of sucrose is 342 g/mole. So, you can apply the following rule of three: If by definition of molar mass 342 grams of the compound are contained in 1 mole, 20 grams of the compound are contained in how many moles?
<u><em>amount of moles= 0.058 moles</em></u>
Now, considering the Avogadro's number, you can apply the following rule of three: If 1 mole of the compound contains 6.023×10²³ molecules, 0.058 moles contains how many molecules?
amount of moleculas= (6.023×10²³ molecules × 0.058 moles)÷ 1 mole
<u><em>amount of molecules= 3.49334×10²² molecules</em></u>
Finally, 3.49334×10²² molecules of sucrose are present.
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- Speed=25m/s
- Time=45min=(45×60)s=2700s
Answer:
7.21 × 10⁴ J
Explanation:
Ethanol is solid below -114.5°c, liquid between -114.5°C and 78.4°C, and gaseous above 78.4°C.
<em>How much heat energy is required to convert 48.3 g of solid ethanol at -114.5°C to gaseous ethanol at 135.3 °C?</em>
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We need to calculate the heat required in different stages and then add them.
The moles of ethanol are:
Solid-liquid transition
Q₁ = ΔHfus . n = (4.60 kJ/mol) . 1.05 mol = 4.83 kJ = 4.83 × 10³ J
where,
ΔHfus: molar heat of fusion
n: moles
Liquid: from -114.5°C to 78.4°C
Q₂ = c(l) . m . ΔT = (2.45 J/g.°C) . 48.3g . [78.4°C-(-114.5°C)] = 2.28 × 10⁴ J
where,
c(l): specific heat capacity of the liquid
ΔT: change in the temperature
Liquid-gas transition
Q₃ = ΔHvap . n = (38.56 kJ/mol) . 1.05 mol = 40.5 kJ = 40.5 × 10³ J
where,
ΔHvap: molar heat of vaporization
Gas: from 78.4°C to 135.3°C
Q₄ = c(g) . m . ΔT = (1.43 J/g.°C) . 48.3g . (135.3°C-78.4°C) = 3.93 × 10³ J
where
c(g): specific heat capacity of the gas
Total heat required
Q₁ + Q₂ + Q₃ + Q₄ = 4.83 × 10³ J + 2.28 × 10⁴ J + 40.5 × 10³ J + 3.93 × 10³ J = 7.21 × 10⁴ J