Numa máquina térmica uma parte da energia térmica fornecida ao sistema(Q1) é transformada em trabalho mecânico (τ) e o restante (Q2) é dissipado, perdido para o ambiente.
sendo:
τ: trabalho realizado (J) [Joule]
Q1: energia fornecida (J)
Q2: energia dissipada (J)
temos: τ = Q1 - Q2
O rendimento (η) é a razão do trabalho realizado pela energia fornecida:
η= τ/Q1
Exercícior resolvido:
Uma máquina térmica cíclica recebe 5000 J de calor de uma fonte quente e realiza trabalho de 3500 J. Calcule o rendimento dessa máquina térmica.
solução:
τ=3500 J
Q1=5000J
η= τ/Q1
η= 3500/5000
η= 0,7 ou seja 70%
Energia dissipada será:
τ = Q1 - Q2
Q2 = Q1- τ
Q2=5000-3500
Q2= 1500 J
Exercicio: Qual seria o rendimento se a máquina do exercicio anterior realizasse 4000J de trabalho com a mesma quantidade de calor fornecida ? Quanta energia seria dissipada agora?
obs: Entregar foto da resolução ou o cálculo passo a passo na mensagem
<span>has four valence electrons in its outermost energy level.
An organic compound in which a carbonyl group is bonded to two different carbon atoms is a(n) ketone.
All of the following release carbon into the atmosphere except the
sedimentation of dead organisms.</span>
Answer:
43.2 mol C
115 mol H
158 mol of atoms
Explanation:
Step 1: Given data
Moles of C₃H₈: 14.4 mol
Step 2: Calculate the number of moles of C
The molar ratio of C₃H₈ to C is 1:3. The moles of C are 3/1 × 14.4 mol = 43.2 mol.
Step 3: Calculate the number of moles of H
The molar ratio of C₃H₈ to H is 1:(. The moles of H are 8/1 × 14.4 mol = 115 mol.
Step 4: Calculate the total number of moles of atoms
n = nC + nH = 43.2 mol + 115 mol = 158 mol
The number of sigma and pi bonds are,
Sigma Bonds =
16 Pi Bonds =
3Explanation: Every first bond formed between two atoms is sigma. Pi bond is formed when already a sigma bond is there. While in case of Alkyne (triple Bond) there is one sigma and one pi bond already present, so the third bond is formed by second side-to-side overlap of orbitals, hence, a second pi bond is formed.
Below all black bonds are sigma bonds, while in alkene there is one pi bond and in alkyne there are two pi bonds.
The choices here are:
<span> a. harder c. more dense b. shinier d. more reactive
The answer is "harder".
The Moh's Scale is also known as the </span><span>Mohs scale of mineral hardness. This scale is basin gon the ability of one certain material to visibly scratch another material. 1 Talc 2 Gypsum 3 Calcite 4 Fluorite 5 Apatite 6 Feldspar 7 Quartz 8 Topaz 9 Corundum 10 Diamond.</span>
