Answer:
Grams
Explanation:
The mass of a penny is closer to the mass of a grape than to the mass of a book. So, use grams to measure the mass of a penny.
<u>Answer:</u> The sample of Carbon-14 isotope is 37056.3 years old
<u>Explanation:</u>
The equation used to calculate rate constant from given half life for first order kinetics:
where,
= half life of the reaction = 5720 years
Putting values in above equation, we get:
Rate law expression for first order kinetics is given by the equation:
where,
k = rate constant =
t = time taken for decay process = ? yr
= initial amount of the sample = 100 grams
[A] = amount left after decay process = (100 - 88.5) = 11.5 grams
Putting values in above equation, we get:
Hence, the sample of Carbon-14 isotope is 37056.3 years old
Answer:
216 g of NO
Explanation:
We begin from the reaction:
4NH₃ + 5O₂ → 4NO + 6H₂O
We determine the limiting reactant with the moles of each reactant:
4 moles of ammonia react to 5 moles of oxygen
Our 7.2 moles of ammonia may react to (7.2 . 5) /4 = 9 moles
It's ok because we have 9.6 moles of oxygen. 0.6 moles still remain.
5 moles of oxygen react to 4 moles of NH₃
Our 9.6 moles of oxygen may react to (9.6 . 4) /5 = 7.68 moles
We only have 7.2 moles of NH₃ and we need 7.68; so there is no enough ammonia and that's our limiting reagent.
Now we determine the moles of product.
4 moles of ammonia can produce 4 moles of NO
Definetely our 7.2 moles, will produce 7.2 moles of oxide.
We convert to mass: 7.2 mol . 30 g/mol = 216 g
Questions:
What instrument is used to measure the mass of different isotopes of an element?
Answer:
Mass spectrometer
The number of atoms in Barium (Ba) is 1