It’s the third one because Cl has 17 protons bc of the numeric number and 18 electrons bc it’s always the opposite and 18 neutrons because you subtract 35-17=18
Answer: 2948
Explanation:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant = 
t = age of sample = ?
a = let initial amount of the reactant = 100
a - x = amount left after decay process = 
Thus the fossil is 2948 years old.
Answer:
Partial pressure of CO₂ is 406.9 mmHg
Explanation:
To solve the question we should apply the concept of the mole fraction.
Mole fraction = Moles of gas / Total moles
We have the total moles of the mixture, if we have the moles for each gas inside. (3.63 moles of O₂, 1.49 moles of N₂ and 4.49 moles of CO₂)
Total moles = 3.63 mol O₂ + 1.49 mol N₂ + 4.49 mol CO₂ = 9.61 moles
To determiine the partial pressure of CO₂ we apply
Mole fraction of CO₂ → mol of CO₂ / Total moles = P. pressure CO₂ / Total P
Partial pressure of CO₂ = (mol of CO₂ / Total moles) . Total pressure
We replace values: (4.49 moles / 9.61 moles) . 871 mmHg = 406.9 mmHg
Hey there!:
Number of moles:
Molar Mass Al = 26.98 g/mol
n = mass / molar mass
n = 9.0 / 26.98
n = 0.3336 moles of Al
Given the reaction :
2 Al + Fe2O3 = Al2O3 + 2 Fe
From the equation, 2 moles of Al give off 849 kJ of heat :
Actual heat given off :
0.3336 / 2 * 849 =
0.3336 / 1698 = 1.4*10² Kj
Hope that helps!
