Answser:
3.77 mg of K-40 decayed into Ar-40.
Data:
1) K-40, Ca-40, Ar-40: all three have the same atomic mass
2) 90%<span> of the potassium-40 will decay into calcium-40
3) 10% of the potassium-40 will decay into argon-40.</span>
4) K-40 inside the rock = 0.81 mg
5) Ar-40 trapped = 0.377 mg
Soltuion:
1) 0.377 mg of Ar-40 is the 10% of the mass of the K-40 that decayed
=> x * 10% = 0.377 mg => x * 0.1 = 0.377mg
=> x = 0.377 mg / 0.1 = 3.77 mg
That means that 3.77 mg of K-40 decayed into Ar-40. And this is the answer to the question.
Additionaly, you can analyze the content of all K-40 and Ca-40, to understand better the case.
2) The mass of the K-40 that decayed into Ca-40 is 9 times (ratio 9:1) the amount that decayed into Ar-40 =>
mass of K-40 that decayed into Ca-40 = 9 * 0.377 = 3.393 mg
3) Total amount of K-40 that decayed = amount that decayed into Ar-40 + amount that decayed into Ca-40 = 0.377mg + 3.393mg = 3.77 mg
4) Original amount of K-40 = amount of K-40 that decayed + amount of K-40 present in the rock = 3.77mg + 0.81 mg = 4.58 mg
5) amount of K-40 that decayed into Ar-40 as percent
% = [3.77 mg / 4.58mg] * 100 = 82.31 %.
4.10 g C12H22O11 * ( 1 mol / 342.2965 g ) * ( 6.022x10^23 / 1 mol ) = <span>7.2107077x10^21 molecules = 7.21x10^21 molecules
Convert grams to moles using the molar mass ( g/mol ).
Use Avogadro's constant ( 6.022x10^23 ) to get the quantity of molecules from the amount of moles.
Revise answer to have the correct number of significant figures ( the smallest amount of digits in any number in the problem is the amount of significant figures your answer should have ).</span>
Answer:
1.239 * 10^8 Kg
Explanation:
Since all the electricity consumed comes from natural gas;
amount of electricity consumed = 700 * 300,000 = 2.1 * 10^8 kWh
So, amount of CO2 consumed is given by;
amount of electricity consumed * amount of CO2 per kWh
Hence,
Amount of CO2 = 2.1 * 10^8 kWh * 0.59 = 1.239 * 10^8 Kg
p = latm
t = 273.15K
R= 0.08206 L atm mol K
75.0g02
16.00 (O₂) = 4.6875mol mol
9
Ideal gas law: PV = nRT, solve for volume: V = nRT P
V =
4.6875mol 0.08206 L-atm mol. K · 273.15K
V = 105L
latm
