<h3>
Answer:</h3>
272.43 K or -0.718°C
<h3>
Explanation:</h3>
We are given;
The initial pressure,P1 as 761 mmHg
Initial temperature, T1 as 0.00°C which is equivalent to 273.15 K
Final pressure as 759 mmHg
We are required to calculate the final temperature;
According to pressure law, the pressure of a gas and absolute temperature are directly proportional at constant volume.
That is; Pα T
Therefore, at varying pressure and temperature,
To get final temperature;
Therefore, the final temperature will be 272.43 K or -0.718°C
Answer:
ΔH°f(C₈H₁₈(g)) = -210.9 kJ/mol
Explanation:
Let's consider the combustion of C₈H₁₈.
C₈H₁₈(g) + 25/2 O₂(g) ⟶ 8 CO₂(g) + 9 H₂O(g) ΔH°rxn = − 5113.3 kJ
We can calculate the standard enthalpy of formation of C₈H₁₈(g) using the following expression.
ΔH°rxn = 8 mol × ΔH°f(CO₂(g)) + 9 mol × ΔH°f(H₂O(g)) - 1 mol × ΔH°f(C₈H₁₈(g)) - 25/2 mol × ΔH°f(O₂(g))
1 mol × ΔH°f(C₈H₁₈(g)) = 8 mol × ΔH°f(CO₂(g)) + 9 mol × ΔH°f(H₂O(g)) - 25/2 mol × ΔH°f(O₂(g)) - ΔH°rxn
1 mol × ΔH°f(C₈H₁₈(g)) = 8 mol × (-393.5 kJ/mol) + 9 mol × (-241.8 kJ/mol) - 25/2 mol × 0 kJ/mol - (− 5113.3 kJ)
ΔH°f(C₈H₁₈(g)) = -210.9 kJ/mol
Answer:
15.7g
Explanation:
mass percent=mass of element/mass of compound *100
39.34=unknown(x)/40g×100
39.34=5x/2
multiplying both sides by 2,we get
5x=78.68
devide by 5 on both sides
x=15.74g Na
The atomic number of Nickle is 28, so its electronic configuration in ground state is,
Ni = 28 e⁻ = 1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d⁸
So, when Nickle looses two electrons it will attain +2 charge, remaining with 26 electrons as,
Ni⁺² = 26 e⁻ = 1s², 2s², 2p⁶, 3s², 3p⁶, 3d⁸
Ni looses electrons from 4s shell instead instead of 3d shell because the 4s shell electrons are at larger distance as compared to 3d, hence, felting less nuclear charge and easily lost.
The best answer is A.
The alimentary canal also called the digestive tract is the pathway by which food enters the body and solid wastes are expelled. The alimentary canal includes the mouth, pharynx esophagus, stomach, small intestine, large intestine and anus.
Food is converted into essential nutrients that are absorbed into the body and eliminates unused waste material. It is essential to good health because if the digestive system shuts down, the body cannot be nourished or rid itself of waste.
